bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, respiration and survival of Legionella pneumophila at high temperatures
Authors: Kusnetsov J.M. , Ottoila E. , Martikainen P.J.
Published: March 2008

The optimum temperature for multiplication of legionella strains in culture media is around 37°C. The effect of high temperatures on the growth of strains isolated from various environments is poorly known. We studied the growth (cell multiplication, respiration) of clinical and environmental Legionella pneumophila strains in liquid media at intervals of 0.5°C in the temperature range from 41.6 to 51.6°C using a temperature gradient incubator. Cell multiplication and CO2 production decreased markedly with all the strains at temperatures above 44–45°C. CO2 continued to be produced up to 51.6C even if cell multiplication generally stopped at around 48.4–50.0C. Thus, legionella retained its metabolic activity beyond the maximum temperature for cell multiplication. The CO2 production per bacterial cell (metabolic quotient, qCO2) increased with increasing temperature up to 45°C, whereafter it decreased, the turning point being almost at the same at which the rate of cell multiplication decreased. The difference in qCO2 between the strains may reflect their different physiological capacities for tolerating high temperatures.
Sensitivity of Bacillus coagulans spores to combinations of high hydrostatic pressure, heat, acidity and nisin
Authors: Roberts C.M. , Hoover D.G.
Published: March 2008

We investigated the combined effects of pressure, temperature, pH, initial spore concentration and the presence of nisin on the survival of spores of Bacillus coagulans. Spores were more sensitive to pressure both at lower pH and at higher treatment temperatures. An additional 1.5‐log10 reduction in cfu ml‐1 was observed when pH was lowered from 7.0 to 4.0 during pressurization at 400 Mpa and 45°C. A 4‐log10 cfu ml‐1 reduction was observed when the temperature was increased from 25°C to 70°C during pressurization at 400 Mpa. The spores were sensitive to nisin at concentrations as low as 0.2 IU ml‐1. At least a 6‐log10 reduction was generally achieved with pressurization at 400 Mpa in pH 4.0 buffer at 70°C for 30 min when plated in nutrient agar containing 0.8 IU ml‐1 nisin.
Note: Comparison of media for the isolation of lactose‐positive Salmonella
Authors: Ruiz J. , Núñez M.L. , Díaz J. , Sempere M.A. , Gömez J. , Usera M.A.
Published: March 2008

We studied the capacity of 10 selective media (Rambach agar, RB; salmonella‐shigella agar, SS; SM‐ID medium, SM; Hektoen enteric agar, HE; modified semisolid Rappaport‐Vassiliadis agar, MSRV; bismuth sulphite agar, BS; MacConkey agar, MC; brilliant green agar, BG; novobiocin‐brilliant green‐glucose agar, NBG; and novobiocin‐brilliant green‐glycerol‐lactose agar, NBGL), and the C8‐esterase test (MUCAP test, Biolife, Italy) to detect the growth of 14 strains of lactose‐positive Salmonella (12 Salm. virchow and two Salm. montevideo) and 16 Salm. arizonae. Suspensions of pure strain were plated on the aforementioned media and on Mueller‐Hinton, used as a control, with inocula of 3 x 102 cfu ml‐1. The performance of BS was excellent, determining the 30 strains as typical Salmonella colonies (H2S+). On NBG, 27 strains were detected. On MSRV, only some strains grew and only one produced swarming. On the other media, the two Salm. montevideo and the 12 Salm. virchow strains produced coliform colonies. Some of these latter were inhibited on BG and NBGL. The 16 Salm. arizonae strains produced typical colonies on all the media, except on RB, SM and MSRV. On NBGL, two strains did not produce H2S. The C8‐esterase test was only successful with Salm. montevideo and Salm. virchow on NBG and RB (with a few exceptions on the latter). However, with Salm. arizonae the test was positive on SS, MC, HE, BG and NBG. In summary, BS was the best medium of those used (all the 30 strains were isolated), followed by NBG (27 isolates).
A solid phase fluorescent capillary immunoassay for the detection of Escherichia coli O157:H7 in ground beef and apple cider
Authors: Czajka J. , Batt C.A.
Published: March 2008

A solid phase fluorescence‐based immunoassay was developed for the detection of Escherichia coli O157:H7 using an antigen down competition format. A soft glass capillary tube served as the solid support, to which heat‐killed E. coli O157:H7 were adsorbed. Polyclonal anti‐E. coli O157:H7 antibody, conjugated with biotin, was used and the bound antigen‐antibody complex was detected using avidin molecules labelled with Cy5, a fluorescent cyanine dye. Any E. coli O157:H7 in the sample would compete with the formation of this complex, reducing fluorescence. This assay was tested for sensitivity with spiked ground beef and apple cider samples. The minimum detectable number of cells present in the initial inoculum was calculated to be approximately 1 colony‐forming unit (cfu) per 10g of ground beef when samples were enriched in modified EC broth for 7 h at 37°C. The minimum detectable number of cells for the apple cider samples was calculated to be ∼0.5 cfu ml‐1 The E. coli cells in the cider samples were captured with immunomagnetic beads, incubated for 7 h in the enrichment broth, and detected with the solid phase fluorescence immunoassay.
Plasmid characterization and pulsed‐field electrophoretic analysis demonstrate that ampicillin‐resistant strains of Salmonella enteritidis phage type 6a are derived from Salm. enteritidis phage type 4
Authors: Ridley A.M. , Punia P. , Ward L.R. , Rowe B. , Threlfall E.J.
Published: March 2008

Plasmid incompatibility studies have demonstrated that strains of Salmonella enteritidis phage type (PT) 6a resistant to ampicillin possess a 36 megadalton incompatibility group (Inc) X plasmid coding for resistance to ampicillin which is capable of converting strains of Salm. enteritidis belonging to PTs 1 and 4 to PT 6a, and PT 8 to PT 13. However, pulsed‐field gel electrophoresis (PFGE) has demonstrated that all clinical isolates of PT 6a have a characteristic Xba I pulsed‐field profile which is distinct from that of PT 1 and which can only be differentiated from that of PT 4 by the presence of plasmid‐associated fragments of less than 45 kb. It is concluded that ampicillin‐resistant strains of Salm. enteritidis PT 6a are derived from strains of Salm. enteritidis PT 4 by acquisition of an Inc X ampicillin resistance plasmid.
A rat model of infection by Salmonella typhimurium or Salm. enteritidis
Authors: Naughton P.J. , Grant G. , Spencer R.J. , Bardocz S. , Pusztai A.
Published: March 2008

Salmonellosis in the rat has many similarities with the disease in humans, with the ileum thought to be the main site of colonization/invasion in both species. Thus, the rat may be a useful way to study the mechanism of infection by these pathogenic bacteria. A series of infection trials carried out with Hooded Lister rats showed that a salmonella infection persisted for an extended period of time and that salmonellae bind to the small intestinal epithelium as early as 4 h after intragastric intubation. Reinfection from the large intestine may not therefore initially play a significant role in the salmonella infection process. The rat model may therefore provide a means to test in vivo interventionist strategies, designed to block binding of the pathogens in the gastrointestinal tract.
Metabolism of 1‐naphthyl‐N‐methyl carbamate (carbaryl) by bacterial isolates from honey bees and the effect of bacterial inoculations on carbaryl tolerance in bees
Authors: Sharma I.D. , Nath A.
Published: March 2008

I.D. SHARMA AND A. NATH. 1996. The bacteria which inhabit the body of foragers of Apis cerana indica F. were evaluated for degradation of carbaryl (1‐naphthyl‐N‐methyl carbamate). Citrobacter sp., Enterobacter aerogenes and an unidentified isolate could utilize carbaryl as sole carbon and energy source. The enrichment cultures of bacteria could degrade carbaryl 0.019–0.082 in nutrient broth and 0.111–7.895 mg μg‐1 bacterial dry wt in basal salts medium of 1 mmol 1‐1 carbaryl. 1‐Naphthol was the major product of carbaryl degradation. The dip and injection inoculations of foragers (Apis cerana indica F. and Apis mellifera L.) with these bacteria resulted in a significant increase in tolerance to carbaryl. The application of mixed culture to bees induced higher tolerance than the individual isolates. This is the first report of the use of bacteria to decontaminate a living system.
Comparative imaging of Pseudomonas putida bacterial biofilms by scanning electron microscopy and both DC contact and AC non‐contact atomic force microscopy
Authors: Gunning P.A. , Kirby A.R. , Parker M.L. , Gunning A.P. , Morris V.J.
Published: March 2008

P.A.GUNNING, A.R.KIRBY, M.L.PARKER, A.P.GUNNING AND V.J.MORRIS. 1996. Both Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) have been used to visualize the morphology of Pseudomonas putida bacterial colonies isolated from model oil‐in‐water emulsions. A new method has been developed for growing flat homogeneous bacterial biofilms at planar oil‐water interfaces. A marked increase in resolution has been achieved when these flat bacterial biofilms are imaged by both SEM and AFM methods. On flat bacterial biofilms AFM offers superior resolution with minimal sample preparation. High resolution DC contact mode AFM studies of the bacterial surfaces have revealed surface features comparable in size to large proteins. AC non‐contact AFM methods have been used to image bacterial flagella trapped in the biofilm.
Fate of genetically modified Rhizobium leguminosarum biovar viciae during long‐term storage of commercial inoculants
Authors: Corich V. , Bosco F. , Giacomini A. , Basaglia M. , Squartini A. , Nuti M.P.
Published: March 2008

V. CORICH, F. BOSCO, A. GIACOMINI, M. BASAGLIA, A. SQUARTINI AND M. P. NUTI. 1996. A study was carried out to assess the behaviour, in terms of strain survival and genetic stability, of genetically modified micro‐organisms (GEMs) during their storage in commercial‐type agricultural inoculants. Three genetically modified Rhizobium leguminosarum biovar viciae strains were constructed, using a gene cassette containing an inducible lacZ gene from Escherichia coli and mercury resistance determinants from transposon Tn1831. In the first case the genes have been integrated into the chromosome, the second strain contains the inducible cassette on a plasmid, in the third case the cassette is carried by the same plasmid, but the lacZ is constitutively expressed at high levels, due to the removal of the regulatory structure (lac operator) between the gene and its promoter. Three inoculum formulations, based on liquid, vermiculite and peat carriers, were prepared using the genetically modified strains, and were monitored during a period of up to 16 months. Results indicate a high stability of the chromosomally integrated markers. The plasmid‐borne modification also was very stable, though the presence of the plasmid affected the strain growth kinetics. In contrast, the strain containing the highly expressed lacZ showed dramatic marker instability. Strain behaviour in stored inoculant packages reflected that observed in batch cultures; moreover, prolonged storage appeared to magnify differences found in in vitro cultures.
Adsorption of bacteriocins by ingestible silica compounds
Authors: Wan J. , Gordon J. , Hickey M.W. , Mawson R.F. , Coventry M.J.
Published: March 2008

Bacteriocins including nisin, pediocin PO2, brevicin 286 and piscicolin 126 were adsorbed from culture supernates by various food‐grade porous silica anti‐caking agents and the food colourant, titanium dioxide. All the porous silica (calcium silicate or silicon dioxide) materials showed substantial capacity in adsorbing bacteriocin activities from the culture supernate and biological activity was recovered in the adsorbents. In contrast, the food colourant titanium dioxide adsorbed most of the bacteriocin activity from the supernate, with minimal biological activity retained in the adsorbent. Experiments with piscicolin 126 showed that optimum adsorption could be achieved with Micro‐Cel E within 30 min, independent of the supernate pH (2.0‐10.0). Piscicolin activity of up to 5 × 107 AU g‐1 of Micro‐Cel E was obtained after adsorption from culture supernates and the adsorbed piscicolin demonstrated substantial biological activity against Listeria monocytogenes in both broth and a milk growth medium.
Inhibition of Salmonella typhimurium by the products of tartrate metabolism by a Veillonella species
Authors: Hinton A. , Hume M.E.
Published: March 2008

The inhibition of the growth of Salmonella typhimurium by a Veillonella species grown on media supplemented with tartrate was examined. Growth of Salmonella typhimurium was not inhibited by the concentrations of products metabolized by Veillonella cultures on media supplemented with 0 or 50 mmol 1‐1 of tartrate, but was inhibited on media supplemented with 100 or 150 mmol 1‐1 of tartrate. Inhibition of Salm. typhimurium was correlated with the increased production of acetate and propionate from tartrate by the Veillonella species.
The Norwegian version of the American pain society patient outcome questionnaire: reliability and validity of three subscales
Authors: Dihle Alfhild , Helseth Sølvi , Christophersen Knut‐Andreas
Published: March 2008

Aims and objectives.  To examine some psychometric properties of the Norwegian version of the American Pain Society's Patient Outcome Questionnaire (APS‐POQ‐N).

Background.  This study is part of an investigation of Norwegian orthopaedic surgical patients, where the overall aim is to evaluate the quality of postoperative pain management. Therefore, an adequate questionnaire on the quality of postoperative pain management was needed.

Methods.  The sample included 114 orthopaedic postoperative patients. The instrument consists of three main subscales, namely the modified Brief Pain Inventory (modified BPI subscale), the subscale on satisfaction with pain management (Satisfaction subscale) and the subscale on beliefs about pain management (Beliefs subscale), together with six single items about pain management. The reliability of these three main subscales was estimated using Cronbach's alpha coefficients and the construct validity was evaluated using principal‐axis factor analysis with oblimin rotation.

Results.  Face and content validity of the APS‐POQ‐N were satisfactory, while the modified BPI and the Beliefs subscales showed acceptable internal consistency but the Satisfaction subscale did not. Factor analyses yielded a three‐factor solution for the modified BPI, a one‐factor solution for the Satisfaction subscale and a two‐factor solution for the Beliefs subscale.

Conclusions.  The APS‐POQ‐N appears, in general, to be an acceptable method of evaluating postoperative pain management in orthopaedic postoperative patients. However, the alpha value of the Satisfaction subscale was low, and thus the subscale is not recommended for this purpose.

Relevance to clinical practice.  Reliable and valid instruments are important when performing clinical research. This instrument is applicable as an indicator of quality of postoperative pain management in clinical practice and research.
A phylogeographical analysis of the range disjunction for foxtail pine (Pinus balfouriana, Pinaceae): the role of Pleistocene glaciation
Authors: ECKERT ANDREW J. , TEARSE BRANDON R. , HALL BENJAMIN D.
Published: March 2008

Biogeographical patterns within the California Floristic Province have been greatly affected by geological and climatic events. Here, we investigate the phylogeography of foxtail pine (Pinus balfouriana) in an effort to date its range disjunction using molecular data and to further our understanding of phylogeographical patterns for plants within the California Floristic Province. The distribution of foxtail pine is characterized by a 500‐km disjunction separating populations located in the Klamath Mountains from those in the southern Sierra Nevada. Previous authors suggested that this disjunction occurred approximately 4000–8000 years ago during the Holocene Xerotherm when western North America became warmer and drier. Those dates, however, are inconsistent with the morphological differences that separate regional populations into formally recognized subspecies. Using the coalescent‐based isolation with migration model and DNA sequence data from the chloroplast, mitochondrial, and nuclear genomes, we evaluate several hypotheses addressing the timing of this range disjunction and its effects on subsequent patterns of gene flow. Results from all three genomes are largely consistent with Middle to Early Pleistocene divergence dates. Those dates correspond to the Sherwin glaciation, which was the largest Pleistocene glacial episode in the Sierra Nevada. Gene flow, moreover, was only documented using data from the chloroplast genome, suggesting that low levels of long‐distance pollen dispersal (Nem < 0.5) have occurred since this divergence event. These results are extended to a discussion of the biogeographical development of subalpine forests in California.
Differences in the mechanism of the allosteric l‐rhamnose responses of the AraC/XylS family transcription activators RhaS and RhaR
Authors: Kolin Ana , Balasubramaniam Vinitha , Skredenske Jeff M. , Wickstrum Jason R. , Egan Susan M.
Published: March 2008

Proteins in the largest subset of AraC/XylS family transcription activators, including RhaS and RhaR, have C‐terminal domains (CTDs) that mediate DNA‐binding and transcription activation, and N‐terminal domains (NTDs) that mediate dimerization and effector binding. The mechanism of the allosteric effector response in this family has been identified only for AraC. Here, we investigated the mechanism by which RhaS and RhaR respond to their effector, l‐rhamnose. Unlike AraC, N‐terminal truncations suggested that RhaS and RhaR do not use an N‐terminal arm to inhibit activity in the absence of effector. We used random mutagenesis to isolate RhaS and RhaR variants with enhanced activation in the absence of l‐rhamnose. NTD substitutions largely clustered around the predicted l‐rhamnose‐binding pockets, suggesting that they mimic the structural outcome of effector binding to the wild‐type proteins. RhaS‐CTD substitutions clustered in the first HTH motif, and suggested that l‐rhamnose induces improved DNA binding. In contrast, RhaR‐CTD substitutions clustered at a single residue in the second HTH motif, at a position consistent with improved RNAP contacts. We propose separate allosteric mechanisms for the two proteins: Without l‐rhamnose, RhaS does not effectively bind DNA while RhaR does not effectively contact RNAP. Upon l‐rhamnose binding, both proteins undergo structural changes that enable transcription activation.
Identification and functional analysis of the Rz/Rz1‐like accessory lysis genes in the membrane‐containing bacteriophage PRD1
Authors: Krupovič Mart , Cvirkaitė‐Krupovič Virginija , Bamford Dennis H.
Published: March 2008

Bacteriophage PRD1 is a tailless membrane‐containing double‐stranded (ds) DNA virus infecting a variety of Gram‐negative bacteria. In order to affect cell lysis, like most dsDNA phages, PRD1 uses the holin‐endolysin system. In this study, we identified two accessory lysis genes, XXXVI and XXXVII, coding for proteins P36 and P37, respectively. Using genetic complementation assays, we show that protein pair P36/P37 is a functional and interchangeable analogue of the Rz/Rz1 of bacteriophage λ. Utilizing molecular biology, electrochemical as well as various microscopic techniques, we characterized the lysis phenotypes of PRD1 host cells infected with mutant viruses. Our results indicate that proteins P36 and P37 confer a competitive advantage to the phage by securing the efficient disruption of the infected cell and consequent release of the phage progeny under less favourable growth conditions. In concordance with prior data and the results obtained in this study, we propose a model explaining the role of Rz/Rz1‐like proteins in the lysis process: Rz/Rz1 complexes transform the mechanical stress caused by the holin lesion at the CM to the OM leading to its disintegration. Finally, identification of the Rz/Rz1‐like genes in PRD1 suggests that tailless icosahedral phages are involved in genetic trade with tailed bacteriophages.
Radial velocity mapping of Paczyński's star AW UMa: not a contact binary
Authors: Pribulla T. , Rucinski S. M.
Published: March 2008

We present 2D (radial velocity, orbital phase) spectroscopic results for the very low mass-ratio close binary AW UMa which strongly indicate that the spectroscopic mass ratio (qsp= 0.10) does not agree with the photometrically derived one and that the widely adopted contact binary model appears to experience serious inconsistencies and limitations for this object. AW UMa is compared with V566 Oph (qsp= 0.26) which we found to behave according to the contact model. Observed broadening functions of AW UMa can be interpreted by a very strong limb darkening and/or non-solid-body rotation of the dominant primary component; the former assumption is unphysical while the differential rotation is not supported by an apparent stability of localized, dark features on the outer side of the primary. There are indications of the existence of an equatorial belt encompassing the whole system. All deficiencies in the interpretation and the discrepancy between the photometric and spectroscopic mass ratio of AW UMa can be solved within a new model of AW UMa where both components are detached and the system is submerged in a stream of hot, optically thick matter which mimics the stellar contact. While the masses and their ratio are correctly given by spectroscopy, the photometric picture is heavily modified by the matter engulfing both stars in the equatorial plane.
Quasimodoana, a new Holarctic genus of eucoiline wasps (Hymenoptera, Cynipoidea, Figitidae), with a phylogenetic analysis of related genera
Authors: FORSHAGE MATTIAS , NORDLANDER GÖRAN , RONQUIST FREDRIK
Published: March 2008

Abstract A new Holarctic genus, Quasimodoana gen.n. is described for the Palearctic eucoiline wasp Eucoila decipiens Förster, 1869, as Quasimodoana decipiens comb.n. A lectotype is designated for this species. A new North American species is described here as Quasimodoana gibba sp.n. As the new genus has similarities with several eucoiline genera, belonging to two related but distinct lineages, a phylogenetic analysis was carried out, based on 83 morphological characters. The two lineages included in the analysis are referred to here under the tribal names of Eucoilini and Trichoplastini stat.nov. We discuss reasons for adopting available tribal names (rather than ‘informal genus groups’), and Trichoplastini is removed from synonymy with Eucoilini. The phylogenetic analysis places Quasimodoana unambiguously within Eucoilini, as a sistergroup to the Trybliographa complex. However, there is only weak support for the monophyly of Eucoilini and for the hypothesized sistergroup relationship between Eucoilini and Trichoplastini.
Green lacewing phylogeny, based on three nuclear genes (Chrysopidae, Neuroptera)
Authors: HARUYAMA NAOTO , MOCHIZUKI ATSUSHI , DUELLI PETER , NAKA HIDESHI , NOMURA MASASHI
Published: March 2008

Abstract Systematic relationships among higher taxa within Chrysopidae, a large and agriculturally significant neuropteran family, are poorly understood. A molecular phylogenetic survey of Chrysopidae was performed with three nuclear genes, namely wingless (546 bp), phosphoenolpyruvate carboxykinase (483 bp), and sodium/potassium ATPase alpha subunit (410 bp). We examined 83 species in 24 genera, mainly from Japan, Eurasia and Africa. Parsimony and Bayesian analyses of combined datasets of a total of 1439 bp demonstrated that (1) monophyly of the subfamily Chrysopinae was supported but the relationship between Nothochrysinae and Apochrysinae was unclear, although the two subfamilies together may constitute the sister taxon of Chrysopinae; (2) of the three tribes examined within Chrysopinae (Ankylopterygini, Belonopterygini and Chrysopini), monophyly of Ankylopterygini and Belonopterygini was supported, but the relationships among the three remain unclear; (3) seven sub‐clades in Chrysopini were indicated, namely (i) Brinckochrysa, (ii) Chrysemosa + Suarius, (iii) Chrysotropia + Nineta, (iv) Mallada + Chrysoperla + Peyerimhoffina, (v) Cunctochrysa + Meleoma + Nipponochrysa + Apertochrysa albolineatoides, (vi) Chrysopa + Plesiochrysa, and (vii) Dichochrysa + Apertochrysa eurydera; and (4) most genera were monophyletic, except for Apertochrysa and Cunctochrysa, each of which was shown to have two distinct origins. Our molecular analysis allowed the assignment of several species of uncertain affinities to known genera. There was some disagreement between the molecular and previously published morphological phylogenies, but in general our results confirmed existing morphological hypotheses of evolution within the family.
Inactivation of the UGPase1 gene causes genic male sterility and endosperm chalkiness in rice (Oryza sativa L.)
Authors: Woo Mi‐Ok , Ham Tae‐Ho , Ji Hyeon‐So , Choi Min‐Seon , Jiang Wenzhu , Chu Sang‐Ho , Piao Rihua , Chin Joong‐Hyoun , Kim Jung‐A , Park Bong Soo , Seo Hak Soo , Jwa Nam‐Soo , McCouch Susan , Koh Hee‐Jong
Published: March 2008

A rice genic male‐sterility gene ms‐h is recessive and has a pleiotropic effect on the chalky endosperm. After fine mapping, nucleotide sequencing analysis of the ms‐h gene revealed a single nucleotide substitution at the 3′‐splice junction of the 14th intron of the UDP‐glucose pyrophosphorylase 1 (UGPase1; EC2.7.7.9) gene, which causes the expression of two mature transcripts with abnormal sizes caused by the aberrant splicing. An in vitro functional assay showed that both proteins encoded by the two abnormal transcripts have no UGPase activity. The suppression of UGPase by the introduction of a UGPase1‐RNAi construct in wild‐type plants nearly eliminated seed set because of the male defect, with developmental retardation similar to the ms‐h mutant phenotype, whereas overexpression of UGPase1 in ms‐h mutant plants restored male fertility and the transformants produced T1 seeds that segregated into normal and chalky endosperms. In addition, both phenotypes were co‐segregated with the UGPase1 transgene in segregating T1 plants, which demonstrates that UGPase1 has functional roles in both male sterility and the development of a chalky endosperm. Our results suggest that UGPase1 plays a key role in pollen development as well as seed carbohydrate metabolism.
Identification of high levels of phytochelatins, glutathione and cadmium in the phloem sap of Brassica napus. A role for thiol‐peptides in the long‐distance transport of cadmium and the effect of cadmium on iron translocation
Authors: Mendoza‐Cózatl David G. , Butko Emerald , Springer Franziska , Torpey Justin W. , Komives Elizabeth A. , Kehr Julia , Schroeder Julian I.
Published: March 2008

Phytochelatins (PCs) are glutathione‐derived peptides that function in heavy metal detoxification in plants and certain fungi. Recent research in Arabidopsis has shown that PCs undergo long‐distance transport between roots and shoots. However, it remains unknown which tissues or vascular systems, xylem or phloem, mediate PC translocation and whether PC transport contributes to physiologically relevant long‐distance transport of cadmium (Cd) between shoots and roots. To address these questions, xylem and phloem sap were obtained from Brassica napus to quantitatively analyze which thiol species are present in response to Cd exposure. High levels of PCs were identified in the phloem sap within 24 h of Cd exposure using combined mass spectrometry and fluorescence HPLC analyses. Unexpectedly, the concentration of Cd was more than four‐fold higher in phloem sap compared to xylem sap. Cadmium exposure dramatically decreased iron levels in xylem and phloem sap whereas other essential heavy metals such as zinc and manganese remained unchanged. Data suggest that Cd inhibits vascular loading of iron but not nicotianamine. The high ratios [PCs]/[Cd] and [glutathione]/[Cd] in the phloem sap suggest that PCs and glutathione (GSH) can function as long‐distance carriers of Cd. In contrast, only traces of PCs were detected in xylem sap. Our results suggest that, in addition to directional xylem Cd transport, the phloem is a major vascular system for long‐distance source to sink transport of Cd as PC–Cd and glutathione–Cd complexes.
Mutations of genes in synthesis of the carotenoid precursors of ABA lead to pre‐harvest sprouting and photo‐oxidation in rice
Authors: Fang Jun , Chai Chenglin , Qian Qian , Li Chunlai , Tang Jiuyou , Sun Lei , Huang Zejun , Guo Xiaoli , Sun Changhui , Liu Min , Zhang Yan , Lu Qingtao , Wang Yiqin , Lu Congming , Han Bin , Chen Fan , Cheng Zhukuan , Chu Chengcai
Published: March 2008

Pre‐harvest sprouting (PHS) or vivipary in cereals is an important agronomic trait that results in significant economic loss. A considerable number of mutations that cause PHS have been identified in several species. However, relatively few viviparous mutants in rice (Oryza sativa L.) have been reported. To explore the mechanism of PHS in rice, we carried out an extensive genetic screening and identified 12 PHS mutants (phs). Based on their phenotypes, these phs mutants were classified into three groups. Here we characterize in detail one of these groups, which contains mutations in genes encoding major enzymes of the carotenoid biosynthesis pathway, including phytoene desaturase (OsPDS), ζ‐carotene desaturase (OsZDS), carotenoid isomerase (OsCRTISO) and lycopene β‐cyclase (β‐OsLCY), which are essential for the biosynthesis of carotenoid precursors of ABA. As expected, the amount of ABA was reduced in all four phs mutants compared with that in the wild type. Chlorophyll fluorescence analysis revealed the occurrence of photoinhibition in the photosystem and decreased capacity for eliminating excess energy by thermal dissipation. The greatly increased activities of reactive oxygen species (ROS) scavenging enzymes, and reduced photosystem (PS) II core proteins CP43, CP47 and D1 in leaves of the Oscrtiso/phs3‐1mutant and OsLCY RNAi transgenic rice indicated that photo‐oxidative damage occurred in PS II, consistent with the accumulation of ROS in these plants. These results suggest that the impairment of carotenoid biosynthesis causes photo‐oxidation and ABA‐deficiency phenotypes, of which the latter is a major factor controlling the PHS trait in rice.
Modelling the population dynamics of Papaver rhoeas under various weed management systems in a Mediterranean climate
Authors: TORRA J , GONZALEZ‐ANDUJAR J L , RECASENS J
Published: March 2008

The demography of the annual dicotyledonous weed Papaver rhoeas and the efficacy of different management practices were studied during three consecutive years in winter cereals in the north‐east of Spain. These data were used to estimate the parameters of a weed life cycle model that was used to describe the population dynamics of this species and to predict the effect of various control strategies and integrated weed management (IWM) scenarios. Without control, the annual rate of increase was 40 (λt), and the minimum control level required to maintain the population stable was 99% of the emerged plants. The annual application of post‐emergence and/or pre‐emergence herbicides did not prevent the growth of the population. Using various cultural control tactics (delayed seeding, harrowing and fallow) resulted in different trends in the overall population depending on the techniques and combinations analysed. Simulations showed that delayed seeding, fallow and pre‐emergence herbicides are the best techniques to employ in IWM programmes, always using a combination of these and other more common practices (i.e. post‐emergence herbicides). Sensitivity analysis indicated interaction between the parameters and that the model was especially sensitive to seed losses and also to fecundity, seedling survivorship and emergence. The study shows that new strategies should be sought to control these parameters. To develop IWM programmes for P. rhoeas, the combination of two or more control strategies is required.
A molecular assay for the proactive detection of target site‐based resistance to herbicides inhibiting acetolactate synthase in Alopecurus myosuroides
Authors: DÉLYE C , BOUCANSAUD K
Published: March 2008

Acetolactate synthase (ALS) inhibitors are the most resistance‐prone herbicide group. Rapid resistance diagnosis is thus of importance for their optimal use. We formulate rules to use the derived cleaved amplified polymorphic sequence method to develop molecular tools detecting a change at a given codon, the nature of which is unknown. We applied them to Alopecurus myosuroides (black grass) to develop assays targeting ALS codons A122, P197, A205, W574 and S653 that are crucial for herbicide sensitivity. These assays detected W574L or P197T, or both substitutions, in most plants analysed from a field where ALS inhibitors failed after 3 years of use. Similar assays can easily be set up for any species. Given the rapidity of selection for resistance to ALS inhibitors, these assays should be very useful in proactive herbicide resistance diagnosis.
Genetic diversity of Moroccan populations of Orobanche foetida: evolving from parasitising wild hosts to crop plants
Authors: VAZ PATTO M C , DÍAZ‐RUIZ R , SATOVIC Z , ROMÁN B , PUJADAS‐SALVÀ A J , RUBIALES D
Published: March 2008

Orobanche foetida is widely distributed in western Mediterranean countries infecting wild legumes. Recently it has been reported in Morocco infecting common vetch, presenting a further constraint for legume production in this area. Comparative studies between Orobanche populations attacking wild species and Orobanche populations growing on crops from the same region may help to clarify whether a host specialisation process occurred. In the present study, the genetic variability of five O. foetida populations, four infecting wild plants and one infecting cultivated vetch in Morocco was characterised using amplified fragment‐length polymorphism (AFLP) markers to elucidate the existing genetic relationship between populations and to suggest a potential origin for the recently detected vetch‐infecting population. Analysis of molecular variance suggested the existence of genotypic differentiation among populations. The most genetic divergent population by cluster analysis was the population collected on Ornithopus sativus. The vetch‐infecting O. foetida population was closer to the three populations infecting Scorpiurus muricatus. The possibility of the presence of a reservoir of diversity is balanced against direct genetic adaptation and completely new introduction. The potential for this Orobanche species to shift host and become a threat to agriculture exists and has to be taken into account for future legume breeding for these areas.
Investigation of killer cell immunoglobulin‐like receptor gene diversity in KIR3DL1 and KIR3DS1 in a transplant population
Authors: Belle I. , Hou L. , Chen M. , Steiner N. K. , Ng J. , Hurley C. K.
Published: March 2008

Several overlapping amplicons were used to obtain the sequence of genomic DNA covering most of the coding regions of KIR3DL1 and KIR3DS1 from a family and 77 bone marrow transplant patients and their unrelated donors. Alleles 3DL1*00101 and *002 were most frequently observed in addition to 12 other known 3DL1 alleles. A single 3DS1 allele, 3DS1*01301, was identified in the 31 of 32 individuals carrying this gene. Two new alleles, 3DL1*01702 and 3DS1*058, were characterized. Three samples appeared to carry the duplicated killer cell immunoglobulin‐like receptor (KIR) haplotype observed in other studies based on the presence of 3DS1 and two 3DL1 alleles. Additionally, one sample appeared to carry a novel KIR haplotype containing one 3DL1 and two 3DS1 alleles.
Expression of pemphigus‐autoantigen desmoglein 1 in human thymus
Authors: Mouquet H. , Berrih‐Aknin S. , Bismuth J. , Joly P. , Gilbert D. , Tron F.
Published: March 2008

Desmoglein (Dsg) 1 is a transmembrane glycoprotein of the desmosome allowing cell–cell adhesion between keratinocytes, whose expression is restricted to stratified squamous epithelia‐like epidermis. Dsg1 is the target autoantigen of pathogenic autoantibodies produced by pemphigus foliaceus and 50% of pemphigus vulgaris patients in a Dsg1‐specific T‐cell‐dependent pathway. Herewith, we show that mRNA of the DSG1 gene is present in normal human thymus and show by quantitative real‐time polymerase chain reaction analysis that the expression of DSG1 transcript increases with age. Although immunoblot analysis on human thymus extracts using different anti‐Dsg1 antibodies did not allow to detect the protein, we show by double‐immunofluorescence assay that Dsg1 is expressed at protein level by CD19+ CD63+ cells located in the medulla. These data provide another illustration of the thymic expression of a tissue‐specific autoantigen involved in an organ‐specific autoimmune disease, which may participate in the tolerance acquisition and/or regulation of Dsg1‐specific T cells.
Identification of a novel HLA‐DRB1 allele, DRB1*116502, by sequence‐based typing in an African‐American individual
Authors: Serov Y. , Hommel‐Berrey G. , Lobashevsky A.
Published: March 2008

The novel allele HLA‐DRB1*116502 differs from HLA‐DRB1*110201 by nucleotide substitutions at codon 59 (GAG→GAC) and 93 (CGG→AGG).
Focal ischemic necrosis in advanced biliary atresia cirrhosis
Authors: Wildhaber Barbara E. , Rubbia‐Brandt Laura , Majno Pietro , Mentha Gilles , Schäppi Michela G. , Anooshiravani Mehrak , Belli Dominique , Chardot Christophe
Published: March 2008

Abstract:  This report correlates the clinical and biological findings, liver hemodynamics and histological features of focal INL in an infant with BA cirrhosis. An eight month old boy with BA, with previous successful porto‐enterostomy, was admitted with signs of cholangitis and ascites. He was treated with antibiotics and diuretics with subsequent clinical improvement. Eight days later, while being fed with hyper‐osmolar milk, he became febrile again: ASAT/ALAT climbed (9000/2300 IU/L), liver function deteriorated. Infectious work‐up was negative. Liver‐ultrasound showed reversed portal flow and a negative arterial diastolic flow. The patient recovered within five days under supportive treatment. A similar event recurred five days later. INL was suspected and semi‐urgent living‐related liver transplantation was performed, with uneventful post‐operative course. Histology of the explanted liver showed extensive foci of INL of different ages. This report illustrates how the association of reversed portal and arterial diastolic flows, with subsequent liver hypoperfusion, may repeatedly cause foci of INL in BA cirrhosis, and lead to rapid progression to liver failure. Because of precarious hepatic blood supply in such patients, close monitoring of portal and diastolic arterial flows is recommended.
2007 IXA Presidential Address. Progress toward an ideal source animal: opportunities and challenges in a changing world
Authors: Sykes Megan
Published: March 2008

Abstract:  Xenotransplantation holds great promise for the treatment of end‐stage organ failure and tissue injury. Recent advances in our understanding of the immunological hurdles to xenotransplantation and the development of genetic modification approaches to overcome them increase the likelihood of success. Exciting advances in these areas were presented at the Joint Congress of the IXA, the Cell Transplant Society and the International Pancreas and Islet Transplant Association in Minneapolis in September, 2007. However, in order to minimize infectious risks and encourage positive public perception of xenotransplantation, clinical trials should be initiated with appropriate monitoring and oversight procedures in place and only when there is high expectation of clinical benefit.
Adoptive transfer of double negative T regulatory cells induces B‐cell death in vivo and alters rejection pattern of rat‐to‐mouse heart transplantation
Authors: Ma Yuexia , He Kathy M. , Garcia Bertha , Min Weiping , Jevnikar Anthony , Zhang Zhu‐Xu
Published: March 2008

Abstract:  Background:  Antibody‐mediated hyperacute and acute graft rejection are major obstacles in achieving long‐term graft survival in xenotransplantation. It is well documented that regulatory T (Treg) cells play a very important role in regulating immune responses to self and non‐self antigens. Our previous studies have shown that TCRαβ+CD3+CD4−CD8− (double negative, DN)‐Treg cells can suppress anti‐donor T‐cell responses and prolong graft survival in allo‐ and xenotransplantation models. We have demonstrated that DN‐Treg cells can induce B‐cell apoptosis in vitro through a perforin‐dependent pathway.

Methods:  B6 mice received rat heart grafts, followed by 14 days of LF15‐0195 treatment. Some mice received Lewis rat cell activated DN‐Treg cells after LF treatment. DN‐Treg cells, purified from perforin−/− mice and from B6 mice pre‐immunized with third party rat cells, were used as controls.

Results:  In this study, we investigated the possibility that adoptive transfer of xenoreactive DN‐Treg cells could suppress B cells in vivo, thus prolonging xenograft survival. We found that apoptotic death of B cells significantly increased after adoptive transfer of DN‐Treg cells. In addition, anti‐donor IgG subtypes were significantly inhibited in the DN‐Treg cell‐treated group, in which the rejection pattern was altered towards cellular‐mediated rejection rather than antibody‐mediated acute vascular rejection. However, perforin‐deficient DN‐Treg cells failed to induce B‐cell death and to prolong heart graft survival, indicating a perforin‐dependent mechanism contributes to B‐cell death in vivo.

Conclusions:  This study suggests that adoptive transfer of xenoreactive DN‐Treg cells can inhibit B‐cell responses in vivo. DN‐Treg cells may be valuable in controlling B‐cell responses in xenotransplantation.
Pre‐treatment of porcine pulmonary xenograft with desmopressin: a novel strategy to attenuate platelet activation and systemic intravascular coagulation in an ex‐vivo model of swine‐to‐human pulmonary xenotransplantation
Authors: Kim Young Tae , Lee Hyun Joo , Lee Sang Woo , Kim Ji Yeon , Wi Hyun Cho , Park Sun Jung , Bae Sung Jin , Kang Hee Jung
Published: March 2008

Abstract:  Background:  Von Willebrand factor (vWF) has been proposed as a major contributor to the development of coagulopathy in pulmonary xenotransplantation. Pretreatment of donor swine with 1‐deamino‐8‐d‐arginine vasopressin (DDAVP), an analog of vasopressin, can reduce the content of vWF in pulmonary xenografts. Here, we investigate the effects of DDAVP pre‐treatment in an ex‐vivo perfusion model of pulmonary xenotransplantation.

Methods:  We set up and performed the ex‐vivo perfusion using porcine pulmonary accessory lobes and fresh human whole blood (n = 12). Half of the donor swine were given 3 μg/kg DDAVP intravenously for 3 days before ex‐vivo perfusion (DDAVP group) and half of them were left untreated (control group). The porcine lung was perfused with fresh blood for 1 h and changes in the following parameters were monitored: pulmonary arterial pressure, pulmonary vascular resistance, blood cell counts, fibrinogen, antithrombin, platelet factor 4, D‐dimer, C3a, C4d, and xenoreactive IgM. The release of Galα1‐3Gal xenoantigen (αGal) from porcine lung which had been perfused and retained for 30 min with human blood was assessed by enzyme‐linked immunosorbent assay using αGal‐binding lectin.

Results:  Both DDAVP and control groups showed typical findings of immediate pulmonary dysfunction: an increase of pulmonary vascular resistance and sequestration of leukocytes and platelets after ex‐vivo perfusion. However, in the DDAVP group, the increase of platelet factor 4, C3a, and C4d after perfusion was attenuated compared to that in the control group. The release of αGal after blood retention was significantly lower in the DDAVP group than that of the control group.

Conclusion:  Pre‐infusion of DDAVP to the donor swine was beneficial in attenuating platelet activation as well as complement/coagulation activation. These effects of DDAVP are likely to relate to the reduction of porcine vWF content in the xenograft. Therefore, the modulation of vWF secretion in donor lungs could be an additional therapeutic way to reduce systemic coagulopathy in pulmonary xenotransplantation.
Prevalence of obesity in mature horses: an equine body condition study
Authors: Thatcher C. D. , Pleasant R. S. , Geor R. J. , Elvinger F. , Negrin K. A. , Franklin J. , Gay L. , Werre S. R.
Published: March 2008

Obesity is becoming a major health concern in horses because of its associations with insulin resistance, oxidative stress/inflammation, and laminitis. However, there is limited information on the prevalence of obesity in horses. The USDA National Animal Health Monitoring System (NAHMS) 1998 Equine study estimated that approximately 1.4% of the U.S. horse population is overweight or obese. The purpose of this study was to determine the prevalence of overweight and obesity in a subpopulation of horses in Virginia. A random sample of 300 mature, Light Breed horses (140 mares, 151 geldings, and 9 stallions) was selected from the VMRCVM Equine Field Service practice. Horses were evaluated during summer 2006. Body Condition Score (BCS) was assigned using a scale of 1 (emaciated) to 9 (obese) by two independent scorers. Neck circumference (cm) was measured at three locations and averaged (ANC). Girth, body length, and height at the withers were measured and used to calculate body weight (BW) and Body Mass Index (BMI). ANC and height at the withers were used to calculate Neck Circumference to Height Ratio (NCHR). Horses were categorized based on BCS as under condition (BCS <4), optimal condition (BCS 4–6), over condition (BCS 6.5–7), and obese condition (BCS 7.5–9). Six horses (2%) were under condition, 141 horses (47%) were in optimal condition, 96 horses (32%) were over condition, and 57 (19%) were obese. BW (p = 0.047), ANC, BMI and NCHR (all p < 0.001) increased with BCS. The prevalence of overweight and obesity in these horses was much higher than previously reported.
Tectonic implications of paleomagnetic data from upper Cretaceous sediments in the Oyubari area, central Hokkaido, Japan
Authors: Tamaki Machiko , Itoh Yasuto
Published: March 2008

Abstract  Paleomagnetic studies provide constraints on the geometric configuration of the eastern Eurasian margin on geological time scales. Characteristic remanent magnetization components were isolated from eight sites by progressive demagnetization executed on samples from 25 sites in the Oyubari area, central Hokkaido where the Late Cretaceous Yezo Group is distributed. After tilt‐correction, all sites show normal polarity site‐mean directions, and well‐clustered directions pass a positive fold test and a correlation test. Planktonic foraminifera indicate an age range of Cenomanian to Turonian, and the studied section is correlated to the geomagnetic polarity chron C34n. Reliable formation‐mean directions that have been corrected for post‐depositional shallowing (D = 7.5°, I = 65.9°, α95 = 6.6°) are characterized by inclination data indicative of no significant latitudinal translation since the Late Cretaceous. Central Hokkaido has, therefore, been situated adjacent to easternmost Mongolia including Sikhote Alin around the present latitude since the Late Cretaceous. Declination data require significant differential rotation between Hokkaido and the eastern Asian margin, which may be indicative of rearrangement of crustal blocks along the continental margin.