bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleukin‐6 (G‐174C) and tumour necrosis factor‐alpha (G‐308A) gene polymorphisms in geriatric patients with chronic periodontitis
Authors: Costa A. M. , Guimarães M. C. M. , De Souza Elias Rosa , Nóbrega O. T. , Bezerra A. C. B.
Published: June 2009

doi:10.1111/j.1741‐2358.2009.00291.x
 
Interleukin‐6 (G‐174C) and tumour necrosis factor‐alpha (G‐308A) gene polymorphisms in geriatric patients with chronic periodontitis

Background and objective:  Periodontitis is a chronic inflammatory disease, and genetic factors may have an important role in its severity. Polymorphisms in the promoter regions of the interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α) genes have been reported to cause changes in the production of these cytokines. The aim of this study was to evaluate the possible role of IL‐6 (G−174C) and tumour necrosis factor (G−308A) polymorphisms, in the severity of chronic periodontitis in an elderly population.

Materials and methods:  In this study, a group of 65 elderly women, comprising 17 patients with moderate chronic periodontitis, 21 with severe chronic periodontitis and 27 healthy patients were selected. DNA was isolated from all subjects, and polymerase chain reaction was used to study the IL‐6 and TNF‐α gene polymorphisms.

Results:  The results of this study showed a significant difference in the allele and genotype frequencies of IL‐6 gene polymorphism between patients with periodontal disease and controls. Subjects carrying the G/G genotype of IL‐6 were most severely affected by periodontitis. The TNF‐α gene polymorphism showed no association with chronic periodontitis between patients and controls.

Conclusion:  The results suggest that the IL‐6 gene polymorphism may be associated with chronic periodontitis, and that TNF‐α gene polymorphism may not be involved in the progression of chronic periodontitis in the population of elderly Brazilian women.
Glass transition temperature of hard chairside reline materials after post‐polymerisation treatments
Authors: Urban Vanessa M. , Machado Ana L. , Alves Marinês O. , Maciel Adeilton P. , Vergani Carlos E. , Leite Edson R.
Published: June 2009

doi:10.1111/j.1741‐2358.2009.00312.x
 
Glass transition temperature of hard chairside reline materials after post‐polymerisation treatments

Objective:  This study evaluated the effect of post‐polymerisation treatments on the glass transition temperature (Tg) of five hard chairside reline materials (Duraliner II‐D, Kooliner‐K, New Truliner‐N, Ufi Gel hard‐U and Tokuso Rebase Fast‐T).

Materials and methods:  Specimens (10 × 10 × 1 mm) were made following the manufacturers’ instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre‐determined power/time combinations, and specimens from the water‐bath group were immersed in hot water at 55°C for 10 min. Glass transition (°C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey’s test (α = 0.05).

Results:  Both post‐polymerisation treatments promoted a significant (p < 0.05) increase in the Tg of reline material K. Materials K, D and N showed the lowest Tg (p < 0.05). No significant difference between T and U specimens was observed.

Conclusion:  Post‐polymerisation treatments improved the glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation.
Development and application of a rapid assessment tool for urban stream networks
Authors: Findlay Sophia , Taylor Mark , Davies Peter , Fletcher Amylia
Published: June 2009

Increasing awareness of the environmental value and importance of catchment systems, coupled with the emergence of legislative demands encouraging a holistic approach to environmental management, has forced practitioners to have a sound understanding of the fluvial systems with which they are working. The collection and interpretation of information regarding the functioning of riparian processes is an integral component of this understanding. This paper details the methods and application of the rapid riparian assessment, which was designed to assess urban stream networks. This tool was developed for Ku‐ring‐gai Council, Sydney, to aid environmental decisions and management processes by collecting meaningful data to identify specific pressures at individual reaches and how these affect catchment processes. These data have been used to identify individual reach and overall catchment condition, and are now guiding capital maintenance programmes to maximise the benefits to natural systems.
Central Nervous System Primitive Neuroectodermal Tumors: A Clinicopathologic and Genetic Study of 33 Cases
Authors: Behdad Amir , Perry Arie
Published: June 2009

Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) include supratentorial, brain stem, and spinal cord tumors with medulloblastoma‐like histopathology. The prognostic impact of various pathologic and genetic features has not been thoroughly investigated. After re‐diagnosis of three infantile cases as atypical teratoid/rhabdoid tumor (AT/RT), 33 remaining CNS PNETs were retrieved for clinicopathologic and fluorescence in situ hybridization studies. Anaplastic and/or large cell features were seen in 18 of 33 (55%) examples and survival was decreased in these patients (P = 0.036). MYCN or MYCC gene amplifications were noted in about half, with a trend towards decreased survival (P = 0.112). Polysomies of chromosomes 2 and 8 were each individually associated with decreased survival in children, with an even stronger association when combined (P = 0.013). Neither EWS gene rearrangements, nor AT/RT‐like 22q deletions were encountered. We conclude that in CNS PNET: (i) routine application of INI1 immunohistochemistry helps rule out AT/RT, particularly in infants; (ii) MYC gene amplifications (especially MYCN) are common; (iii) involvement of CNS parenchyma by Ewing sarcoma/peripheral PNET is rare enough that EWS gene testing is not necessary unless significant dural involvement is present; and (iv) both anaplastic/large cell features and polysomies of 2 and 8 are associated with more aggressive clinical behavior.
MECANISME D'OXYDATION PHOTOSENSIBILISEE DANS UN MILIEU RIGIDE MACROMOLECULAIRE
Authors: Bourdon J. , Schnuriger B.
Published: June 2009

Abstract— The photosensitized oxidation of 4‐methoxynaphthol by erythrosin is studied in a film of ethylcellulose which acts in this reaction as a binder, permeable to oxygen. The rate of the oxidation of the naphthol is measured as a function of the average intermolecular distance. It is shown that sensitized photo‐oxidation occurs in such rigid medium with a rather high quantum yield (0·2‐0·3) and that the quantum yield remains high when the intermolecular distance increases up to a value which is large (80 Å) compared to the molecular size. As a consequence, it seems that such a reaction cannot proceed without the intervention of an oxidizing entity able to diffuse in the rigid binder. Such an entity can be O2, as proposed by Kautsky, as well as H2O2 or the ion O2−.

A strong effect of deactivation of the sensitizer by a resonance energy transfer process has been shown to take place in the film when the average distance between dye molecules is less than about 120 Å. This deactivation of the sensitizer appears as fluorescence quenching and as a decrease in the rate of the reaction when the intermolecular distance decreases. At very short distances another mechanism seems to occur which results in a higher quantum yield.
UEBER DIE HALTBARKEIT VON KOKAINLÖSUNGEN BEIM STERILISIEREN
Authors: Nordlöw W.
Published: June 2009

Hier ausgeführte Untersuchungen unter Anwendung der Oberflächensensibilität der menschlichen Hornhaut als Wertmesser ergaben:

Dass die anästhesierende Wirkung einer wässrigen Lösung des Kokains bie wiederholtem Sterilisieren (Kochen bei 100°) sich nicht ändert.

Dass Änderung des PH der Lösung, die beim Kochen in Gläsern, die kein Alkali abgeben, entstehen, für die Tropfanästhesie ohne Bedeutung sind.

Dass eine Steigerung des PH, auf 7, 39 wahrscheinlich keinen gesteigerten lokalanästhetischen Effekt hervorruft.
JUDICIA DE NOVIS LIBRIS
Authors: Brændstrup Poul
Published: June 2009

Fortschritte der Augenheilkunde — Advances in Ophthalmology — Progrès en Ophtalmologie, Vol. IV, edited by E. B. Streiff, Lausanne. (Bibliotheca Ophthalmologica, fasc. 42). S. Karger. Basel — New York. Pp. 328. Price S. Fr. 39,50.

van Beuningen, E. G. A.: Atlas der Spaltlampengonioskopie. 1995. Leipzig. VEB Georg Thieme. Pp. 124. III. 141. Price: D.M.59.
JUDICIA DE NOVIS LIBRIS
Authors: Ehlers Holger , Brændstrup Poul , Brændstrup Paul , Brændstrup Paul , Brændstrup Paul
Published: June 2009

Gasteiger, H., Augenheilkunde (Der Kliniker)

Schmöger, Elisabeth:

Ophtalmologie, tome I + II, in l'Encyclopédie Médico‐Chirurgicale.

Fortschritte der Augenheilkunde—Advances in Ophthalmology—Progrès en Ophtalmologie.

Pirie, Antoinette & Ruth van Heyningen:
Analysis of the short‐term effect of two viscoelastic agents on the intraocular pressure after extracapsular cataract extraction
Authors: Storr‐Paulsen Allan
Published: June 2009

Abstract We conducted a study to evaluate the short‐term effect on intraocular pressure (IOP) following extracapsular cataract extraction using either sodium hyaluronate 1% or hydroxypropyl methylcellulose 2%. In both groups a non‐significant rise in IOP at day 1 was followed by a significant decline in IOP at day 3 to values below the pre‐operative level (p < 0.05). At day 7 both groups had returned to pre‐operative values. Post‐operatively, spikes in intraocular pressure (> 25 mmHg) were seen equally in both groups. Patients with pre‐operatively diagnosed open‐angle glaucoma, high myopia and diabetic retinopathy are considered to be at high risk concerning post‐operatively elevated IOP, but with small variation these patients followed the main trend.
Accuracy of Goldmann tonometry in clinical practice
Authors: Sudesh Sudha , Moseley Merrick J. , Thompson John R.
Published: June 2009

Abstract The intra‐ and inter‐observer variability of Goldmann applanation tonometry was studied in 8 hospital tonometrists, 4 of whom received brief revision training in tonometer use. Intraocular pressure (IOP) measurements were obtained from 16 glaucoma patients. Over a series of four readings taken from individual eyes, intraocular pressure did not significantly vary. However, a decline in IOP was observed when a second tonometrist obtained a further series of four readings from a previously measured eye. Mean pressures recorded by tonometrists who had received revision training were greater than those obtained by the untrained observers though this could be accounted for by two highly experienced individuals in the untrained group who tended to record low pressures. Comparisons of average readings obtained by two observers on the same eye showed that approximately one‐quarter of measurements differed by 2 or more mmHg and approximately one‐fifth by 3 or more mmHg.
Elevated intraocular pressure and pseudoexfoliation of the lens capsule as risk factors for chronic open‐angle glaucoma
Authors: Ekström Curt
Published: June 2009

Abstract In 1984‐86, a glaucoma survey was carried out in a municipality in central Sweden, comprising 760 subjects 65–74 years of age. Since 1988, a follow‐up study of those 527 subjects who had normal and reliable visual fields has been in progress. A visual field defect was required for a diagnosis of chronic open‐angle glaucoma. By December 1991, 10 cases of capsular glaucoma and 3 cases of chronic simple glaucoma had been found. The standardized relative risk for chronic open‐angle glaucoma was 3.4 times (95% confidence interval: 1.1 ‐ 11) greater in subjects with a baseline intraocular pressure < 21 mmHg, using the highest pressure in either eye, than in those with an intraocular pressure < 21 mmHg. Pseudoexfoliation increased the standardized relative risk 9.8‐fold (95% confidence interval: 2.5 – 38). There was indication of effect modification between intraocular pressure and pseudoexfoliation. Optic disc haemorrhages were associated with a 4.8‐fold (95% confidence interval: 0.63 – 37) increased unadjusted risk. The study supports the pressure theory of optic nerve damage in glaucoma. Pseudoexfoliation was recognized as an independent risk factor for the development of chronic open‐angle glaucoma.
Conversion, Evangelism and Market
Authors: Dibeela Moiseraele Prince
Published: June 2009

This article revisits the old theological notions of conversion and evangelism. These are vital theological ideas, which are revisited here in the light of the challenges of the neoliberal market economy. These concepts have often been used in conservative ways and with limited scope. The paper attempts to redeem their potency and invites us to reconsider our understanding of these issues. The discussion locates the evangelical task of the church within the context of the ravages and inequalities precipitated by the dominant economy. The paper also makes some theological propositions for a new evangelical movement borne out of a grappling with the biblical text and praxis.
Reconciliation and the New Identity in Christ: Pneumatological Perspectives of Christian Mission in its Third Millennium
Authors: Grundmann Christoffer H.
Published: June 2009

Stimulated by the theme of the 2008 International Association for Mission Studies' general conference on “Human Identity and the Gospel of Reconciliation”, the article first screens the respective biblical terminology and texts and then ponders general theological considerations of the topic. In a third part, missiological implications that arise are shown and conclusions drawn for an appropriate contemporary missionary attitude. Reconciliation and identity are oftentimes mutually exclusive since the quest for national and cultural identity has the potential to turn into violent clashes. However, the new identity in Christ taken on in baptism and faith implies the realization by people of their reconciliation with God by God and, by this, with everyone else. The implications of this new identity challenge established perceptions of justice and call everyone to live accordingly. Since Christian faith will only be known when it is shared, mission today has to be lived advocacy for the spirit of God as embodied in Jesus Christ and carried out in a truly kenotic attitude that is also prepared to endure marginality and vulnerability as expressions of its eschatological nature.
Nonaxisymmetric Three-Dimensional Stagnation-Point Flow and Heat Transfer on a Flat Plate
Authors: Abbassi Ali Shokrgozar , Rahimi Asghar Baradaran
Published: June 2009

The existing solutions of Navier–Stokes and energy equations in the literature regarding the three-dimensional problem of stagnation-point flow either on a flat plate or on a cylinder are only for the case of axisymmetric formulation. The only exception is the study of three-dimensional stagnation-point flow on a flat plate by Howarth (1951, “The Boundary Layer in Three-Dimensional Flow—Part II: The Flow Near Stagnation Point,” Philos. Mag., 42, pp. 1433–1440), which is based on boundary layer theory approximation and zero pressure assumption in direction of normal to the surface. In our study the nonaxisymmetric three-dimensional steady viscous stagnation-point flow and heat transfer in the vicinity of a flat plate are investigated based on potential flow theory, which is the most general solution. An external fluid, along z-direction, with strain rate a impinges on this flat plate and produces a two-dimensional flow with different components of velocity on the plate. This situation may happen if the flow pattern on the plate is bounded from both sides in one of the directions, for example x-axis, because of any physical limitation. A similarity solution of the Navier–Stokes equations and energy equation is presented in this problem. A reduction in these equations is obtained by the use of appropriate similarity transformations. Velocity profiles and surface stress-tensors and temperature profiles along with pressure profile are presented for different values of velocity ratios, and Prandtl number.
Unsteady Flow Patterns for a Double Suction Centrifugal Pump
Authors: González José , Fernández Oro Jesús Manuel , Argüelles Díaz Katia M. , Blanco Eduardo
Published: June 2009

The flow in a double suction centrifugal pump is presented in this paper. The static performance of the machine has been obtained in a proper test rig, and the results have been compared with equivalent numerical results from an Unsteady Reynolds Averaged Navier–Stokes Equations (URANS) calculation. In a second step, the numerical results have been exploited to get detailed information about the flow inside the turbomachine. The main goal of the study is, on one hand, the validation of the numerical procedure proposed and, on the other hand, the detailed flow-field analysis for the machine, which points out the possibilities and drawbacks of the pump design. For a double suction machine, the inlet flow is characterized by the existence of a particular geometry that tries to force a uniform flow, at least for the nominal flow rate. On the contrary, at off-design conditions the lack of uniformity produces an unsteady incidence that gives rise to strong hydraulic loading variations. Instantaneous and average pressure fields have been analyzed in this paper to study the evolution of such inlet flow unsteadiness throughout the impeller and the volute. The analysis of both static and dynamic effects on the pump shaft has been carried out from the numerical calculation of the radial forces. The results have shown that the performance of the double suction centrifugal pump is suitable for typical design conditions. The best operation point or nominal flow rate is found to be at φ=0.274, which turns out to produce a specific speed ωS=1.25, well in the range for centrifugal impellers. This operating point is also found to be the one with better efficiency and with better flow characteristics, regarding the axisymmetry of the flow pattern and the fluid forces obtained. However, some particular features produce also interesting results for off-design operating points.
Trapping Molecules on a Chip
Authors: Meek Samuel A. , Conrad Horst , Meijer Gerard
Published: June 2009

CO on a Chip

Microfluidics technology has facilitated remarkable miniaturization of chemical synthesis platforms; through electrically gated solution flow and mixing, molecular reactions can be carried out on chips several centimeters across. When it comes to more fundamental dynamics studies, though, which involve probing gas-phase molecules in specific quantum mechanical states, the experiments still tend to require much larger interaction areas.

Meek
et al.

(p.
1699
) take a step toward miniaturization in this latter regime by demonstrating the isolation of a cold gas-phase beam of CO molecules just above a microelectrode-decorated chip. The technique relies on rapidly modulated electric fields that trap and then slow down the incoming molecules through dipole interactions. Once brought to a stop, the molecules can be held on the chip for a discrete period and then released to a detector.
Discovery of Untracked Pathogen Vials at Army Lab Sparks Concerns
Authors: Bhattacharjee Yudhijit
Published: June 2009

More than 9200 unlisted vials of dangerous pathogens and toxins have turned up in an inventory of biological materials at the U.S. Army Medical Research Institute of Infectious Diseases in Fort Detrick, Maryland.
Bacterial and Archaeal Phylogenetic Diversity of a Cold Sulfur-Rich Spring on the Shoreline of Lake Erie, Michigan
Authors: Chaudhary Anita , Haack Sheridan Kidd , Duris Joseph W. , Marsh Terence L.
Published: June 2009

Studies of sulfidic springs have provided new insights into microbial metabolism, groundwater biogeochemistry, and geologic processes. We investigated Great Sulphur Spring on the western shore of Lake Erie and evaluated the phylogenetic affiliations of 189 bacterial and 77 archaeal 16S rRNA gene sequences from three habitats: the spring origin (11-m depth), bacterial-algal mats on the spring pond surface, and whitish filamentous materials from the spring drain. Water from the spring origin water was cold, pH 6.3, and anoxic (H
2
, 5.4 nM; CH
4
, 2.70 μM) with concentrations of S
2−
(0.03 mM), SO
4
2−
(14.8 mM), Ca
2+
(15.7 mM), and HCO
3
−
(4.1 mM) similar to those in groundwater from the local aquifer. No archaeal and few bacterial sequences were >95% similar to sequences of cultivated organisms. Bacterial sequences were largely affiliated with sulfur-metabolizing or chemolithotrophic taxa in
Beta
-,
Gamma
-,
Delta
-, and
Epsilonproteobacteria
.
Epsilonproteobacteria
sequences similar to those obtained from other sulfidic environments and a new clade of
Cyanobacteria
sequences were particularly abundant (16% and 40%, respectively) in the spring origin clone library.
Crenarchaeota
sequences associated with archaeal-bacterial consortia in whitish filaments at a German sulfidic spring were detected only in a similar habitat at Great Sulphur Spring. This study expands the geographic distribution of many uncultured
Archaea
and
Bacteria
sequences to the Laurentian Great Lakes, indicates possible roles for epsilonproteobacteria in local aquifer chemistry and karst formation, documents new oscillatorioid
Cyanobacteria
lineages, and shows that uncultured, cold-adapted
Crenarchaeota
sequences may comprise a significant part of the microbial community of some sulfidic environments.
A NewBorreliaSpecies Defined by Multilocus Sequence Analysis of Housekeeping Genes
Authors: Margos Gabriele , Vollmer Stephanie A. , Cornet Muriel , Garnier Martine , Fingerle Volker , Wilske Bettina , Bormane Antra , Vitorino Liliana , Collares-Pereira Margarida , Drancourt Michel , Kurtenbach Klaus
Published: June 2009

Analysis of Lyme borreliosis (LB) spirochetes, using a novel multilocus sequence analysis scheme, revealed that OspA serotype 4 strains (a rodent-associated ecotype) ofBorrelia gariniiwere sufficiently genetically distinct from bird-associatedB. gariniistrains to deserve species status. We suggest that OspA serotype 4 strains be raised to species status and namedBorrelia bavariensissp. nov. The rooted phylogenetic trees provide novel insights into the evolutionary history of LB spirochetes.
Energy Taxis Drives
Campylobacter jejuni
toward the Most Favorable Conditions for Growth
Authors: Vegge Christina S. , Brøndsted Lone , Li Yi-Ping , Bang Dang D. , Ingmer Hanne
Published: June 2009

Campylobacter jejuni
is a serious food-borne bacterial pathogen in the developed world. Poultry is a major reservoir, and
C. jejuni
appears highly adapted to the gastrointestinal tract of birds. Several factors are important for chicken colonization and virulence, including a taxis mechanism for environmental navigation. To explore the mechanism of chemotaxis in
C. jejuni
, we constructed mutants with deletions of five putative
mcp
(methyl-accepting chemotaxis protein) genes (
tlp1
,
tlp2
,
tlp3
,
docB
, and
docC
). Surprisingly, the deletions did not affect the chemotactic behavior of the mutants compared to that of the parental strain. However, the
tlp1
,
tlp3
,
docB
, and
docC
mutant strains displayed a 10-fold decrease in the ability to invade human epithelial and chicken embryo cells, hence demonstrating that the corresponding proteins affect the host interaction.
l
-Asparagine, formate,
d
-lactate, and chicken mucus were identified as new attractants of
C. jejuni
, and we observed that chemical substances promoting tactic attraction are all known to support the growth of this organism. The attractants could be categorized as carbon sources and electron donors and acceptors, and we furthermore observed a correlation between an attractant's potency and its efficiency as an energy source. The tactic attraction was inhibited by the respiratory inhibitors HQNO (2-
n
-heptyl-4-hydroxyquinoline
N
-oxide) and sodium azide, which significantly reduce energy production by oxidative phosphorylation. These findings strongly indicate that energy taxis is the primary force in environmental navigation by
C. jejuni
and that this mechanism drives the organism toward the optimal chemical conditions for energy generation and colonization.
Chickens and Cattle as Sources of Sporadic Domestically Acquired
Campylobacter jejuni
Infections in Finland
Authors: Hakkinen Marjaana , Nakari Ulla-Maija , Siitonen Anja
Published: June 2009

A substantial sampling among domestic human campylobacter cases, chicken process lots, and cattle at slaughter was performed during the seasonal peak of human infections.
Campylobacter jejuni
isolates (
n
= 419) were subtyped using pulsed-field gel electrophoresis with SmaI, and isolates representing overlapping types (
n
= 212) were further subtyped using KpnI for restriction. The SmaI/KpnI profiles of 55.4% (97/175) of the human isolates were indistinguishable from those of the chicken or cattle isolates. The overlapping SmaI/KpnI subtypes accounted for 69.8% (30/43) and 15.9% (32/201) of the chicken and cattle isolates, respectively. The occurrence of identical SmaI/KpnI subtypes with human
C. jejuni
isolates was significantly associated with animal host species (
P
< 0.001). A temporal association of isolates from chickens and patients was possible in 31.4% (55/175) of the human infections. Besides chickens as sources of
C. jejuni
in the sporadic infections, the role of cattle appears notable. New approaches to restrict the occurrence of campylobacters in other farm animals may be needed in addition to hygienic measures in chicken production. However, only about half of the human infections were attributable to these sources.
Role of Growth Temperature in Freeze-Thaw Tolerance of
Listeria
spp
Authors: Azizoglu Reha O. , Osborne J. , Wilson S. , Kathariou S.
Published: June 2009

The food-borne pathogen
Listeria monocytogenes
can grow in a wide range of temperatures, and several key virulence determinants of the organism are expressed at 37°C but are strongly repressed below 30°C. However, the impact of growth temperature on the ability of the bacteria to tolerate environmental stresses remains poorly understood. In other microorganisms, cold acclimation resulted in enhanced tolerance against freezing and thawing (cryotolerance). In this study, we investigated the impact of growth temperature (4, 25, and 37°C) on the cryotolerance of 14 strains of
L. monocytogenes
from outbreaks and from food processing plant environments and four strains of nonpathogenic
Listeria
spp. (
L. welshimeri
and
L. innocua
). After growth at different temperatures, cells were frozen at −20°C, and repeated freeze-thaw cycles were applied every 24 h. Pronounced cryotolerance was exhibited by cells grown at 37°C, with a <1-log decrease after 18 cycles of freezing and thawing. In contrast, freeze-thaw tolerance was significantly reduced (
P
< 0.05) when bacteria were grown at either 4 or 25°C, with log decreases after 18 freeze-thaw cycles ranging from 2 to >4, depending on the strain. These findings suggest that growth at 37°C, a temperature required for expression of virulence determinants of
L. monocytogenes
, is also required for protection against freeze-thaw stress. The negative impact of growth at low temperature on freeze-thaw stress was unexpected and has not been reported before with this or other psychrotrophic microorganisms.
Prevalence of
Escherichia coli
O157:H7 in Organically and Naturally Raised Beef Cattle
Authors: Reinstein S. , Fox J. T. , Shi X. , Alam M. J. , Renter D. G. , Nagaraja T. G.
Published: June 2009

We determined the prevalence of
Escherichia coli
O157:H7 in organically and naturally raised beef cattle at slaughter and compared antibiotic susceptibility profiles of the isolates to those of isolates from conventionally raised beef cattle. The prevalences of
E. coli
O157:H7 were 14.8 and 14.2% for organically and naturally raised cattle, respectively. No major difference in antibiotic susceptibility patterns among the isolates was observed.
Bacillus thuringiensisBel Protein Enhances the Toxicity of Cry1Ac Protein toHelicoverpa armigeraLarvae by Degrading Insect Intestinal Mucin
Authors: Fang Shangling , Wang Li , Guo Wei , Zhang Xia , Peng Donghai , Luo Chunping , Yu Ziniu , Sun Ming
Published: June 2009

Bacillus thuringiensishas been used as a bioinsecticide to control agricultural insects.Bacillus cereusgroup genomes were found to have aBacillusenhancin-like (bel) gene, encoding a peptide with 20 to 30% identity to viral enhancin protein, which can enhance viral infection by degradation of the peritrophic matrix (PM) of the insect midgut. In this study, thebelgene was found to have an activity similar to that of the viral enhancin gene. Abelknockout mutant was constructed by using a plasmid-freeB. thuringiensisderivative, BMB171. The 50% lethal concentrations of this mutant plus thecry1Acinsecticidal protein gene were about 5.8-fold higher than those of the BMB171 strain. When purified Bel was mixed with the Cry1Ac protein and fed toHelicoverpa armigeralarvae, 3 μg/ml Cry1Ac alone induced 34.2% mortality. Meanwhile, the mortality rate rose to 74.4% when the same amount of Cry1Ac was mixed with 0.8 μg/ml of Bel. Microscopic observation showed a significant disruption detected on the midgut PM ofH. armigeralarvae after they were fed Bel. In vitro degradation assays showed that Bel digested the intestinal mucin (IIM) ofTrichoplusia niandH. armigeralarvae to various degrading products, similar to findings for viral enhancin. These results imply Bel toxicity enhancement depends on the destruction of midgut PM and IIM, similar to the case with viral enhancin. This discovery showed that Bel has the potential to enhance insecticidal activity ofB. thuringiensis-based biopesticides and transgenic crops.
Kinetic Characterization of OmcA and MtrC, Terminal Reductases Involved in Respiratory Electron Transfer for Dissimilatory Iron Reduction in
Shewanella oneidensis
MR-1
Authors: Ross Daniel E. , Brantley Susan L. , Tien Ming
Published: June 2009

We have used scaling kinetics and the concept of kinetic competence to elucidate the role of hemeproteins OmcA and MtrC in iron reduction by
Shewanella oneidensis
MR-1. Second-order rate constants for OmcA and MtrC were determined by single-turnover experiments. For soluble iron species, a stopped-flow apparatus was used, and for the less reactive iron oxide goethite, a conventional spectrophotometer was used to measure rates. Steady-state experiments were performed to obtain molecular rate constants by quantifying the OmcA and MtrC contents of membrane fractions and whole cells by Western blot analysis. For reduction of soluble iron, rates determined from transient-state experiments were able to account for rates obtained from steady-state experiments. However, this was not true with goethite; rate constants determined from transient-state experiments were 100 to 1,000 times slower than those calculated from steady-state experiments with membrane fractions and whole cells. In contrast, addition of flavins to the goethite experiments resulted in rates that were consistent with both transient- and steady-state experiments. Kinetic simulations of steady-state results with kinetic constants obtained from transient-state experiments supported flavin involvement. Therefore, we show for the first time that OmcA and MtrC are kinetically competent to account for catalysis of soluble iron reduction in whole
Shewanella
cells but are not responsible for electron transfer via direct contact alone with insoluble iron-containing minerals. This work supports the hypothesis that electron shuttles are important participants in the reduction of solid Fe phases by this organism.
Novel Denitrifying Bacterium
Ochrobactrum anthropi
YD50.2 Tolerates High Levels of Reactive Nitrogen Oxides
Authors: Doi Yuki , Takaya Naoki , Takizawa Noboru
Published: June 2009

Most studies of bacterial denitrification have used nitrate (NO
3
−
) as the first electron acceptor, whereas relatively less is understood about nitrite (NO
2
−
) denitrification. We isolated novel bacteria that proliferated in the presence of high levels of NO
2
−
(72 mM). Strain YD50.2, among several isolates, was taxonomically positioned within the α subclass of
Proteobacteria
and identified as
Ochrobactrum anthropi
YD50.2. This strain denitrified NO
2
−
, as well as NO
3
−
. The gene clusters for denitrification (
nar
,
nir
,
nor
, and
nos
) were cloned from
O. anthropi
YD50.2, in which the
nir
and
nor
operons were linked. We confirmed that
nirK
in the
nir
-
nor
operon produced a functional NO
2
−
reductase containing copper that was involved in bacterial NO
2
−
reduction. The strain denitrified up to 40 mM NO
2
−
to dinitrogen under anaerobic conditions in which other denitrifiers or NO
3
−
reducers such as
Pseudomonas aeruginosa
and
Ralstonia eutropha
and nitrate-respiring
Escherichia coli
neither proliferated nor reduced NO
2
−
. Under nondenitrifying aerobic conditions,
O. anthropi
YD50.2 and its type strain ATCC 49188
T
proliferated even in the presence of higher levels of NO
2
−
(100 mM), and both were considerably more resistant to acidic NO
2
−
than were the other strains noted above. These results indicated that
O. anthropi
YD50.2 is a novel denitrifier that has evolved reactive nitrogen oxide tolerance mechanisms.
Roles of Small, Acid-Soluble Spore Proteins and Core Water Content in Survival of
Bacillus subtilis
Spores Exposed to Environmental Solar UV Radiation
Authors: Moeller Ralf , Setlow Peter , Reitz Günther , Nicholson Wayne L.
Published: June 2009

Spores of
Bacillus subtilis
contain a number of small, acid-soluble spore proteins (SASP) which comprise up to 20% of total spore core protein. The multiple α/β-type SASP have been shown to confer resistance to UV radiation, heat, peroxides, and other sporicidal treatments. In this study, SASP-defective mutants of
B. subtilis
and spores deficient in
dacB
, a mutation leading to an increased core water content, were used to study the relative contributions of SASP and increased core water content to spore resistance to germicidal 254-nm and simulated environmental UV exposure (280 to 400 nm, 290 to 400 nm, and 320 to 400 nm). Spores of strains carrying mutations in
sspA
,
sspB
, and both
sspA
and
sspB
(lacking the major SASP-α and/or SASP-β) were significantly more sensitive to 254-nm and all polychromatic UV exposures, whereas the UV resistance of spores of the
sspE
strain (lacking SASP-γ) was essentially identical to that of the wild type. Spores of the
dacB
-defective strain were as resistant to 254-nm UV-C radiation as wild-type spores. However, spores of the
dacB
strain were significantly more sensitive than wild-type spores to environmental UV treatments of >280 nm. Air-dried spores of the
dacB
mutant strain had a significantly higher water content than air-dried wild-type spores. Our results indicate that α/β-type SASP and decreased spore core water content play an essential role in spore resistance to environmentally relevant UV wavelengths whereas SASP-γ does not.
Genetic Diversity and Multihost Pathogenicity of Clinical and Environmental Strains ofBurkholderia cenocepacia
Authors: Springman A. Cody , Jacobs Janette L. , Somvanshi Vishal S. , Sundin George W. , Mulks Martha H. , Whittam Thomas S. , Viswanathan Poorna , Gray R. Lucas , LiPuma John J. , Ciche Todd A.
Published: June 2009

A collection of 54 clinical and agricultural isolates ofBurkholderia cenocepaciawas analyzed for genetic relatedness by using multilocus sequence typing (MLST), pathogenicity by using onion and nematode infection models, antifungal activity, and the distribution of three marker genes associated with virulence. The majority of clinical isolates were obtained from cystic fibrosis (CF) patients in Michigan, and the agricultural isolates were predominantly from Michigan onion fields. MLST analysis resolved 23 distinct sequence types (STs), 11 of which were novel. Twenty-six of 27 clinical isolates from Michigan were genotyped as ST-40, previously identified as the MidwestB. cenocepacialineage. In contrast, the 12 agricultural isolates represented eight STs, including ST-122, that were identical to clinical isolates of the PHDC lineage. In general, pathogenicity to onions and the presence of thepehAendopolygalacturonase gene were detected only in one cluster of related strains consisting of agricultural isolates and the PHDC lineage. Surprisingly, these strains were highly pathogenic in the nematodeCaenorhabditis elegansinfection model, killing nematodes faster than the CF pathogenPseudomonas aeruginosaPA14 on slow-kill medium. The other strains displayed a wide range of pathogenicity toC. elegans, notably the Midwest clonal lineage which displayed high, moderate, and low virulence. Most strains displayed moderate antifungal activity, although strains with high and low activities were also detected. We conclude that pathogenicity to multiple hosts may be a key factor contributing to the potential ofB. cenocepaciato opportunistically infect humans both by increasing the prevalence of the organism in the environment, thereby increasing exposure to vulnerable hosts, and by the selection of virulence factors that function in multiple hosts.
Identification of Three Alcohol Dehydrogenase Genes Involved in the Stereospecific Catabolism of Arylglycerol-β-Aryl Ether by
Sphingobium
sp. Strain SYK-6
Authors: Sato Yusuke , Moriuchi Hideki , Hishiyama Shojiro , Otsuka Yuichiro , Oshima Kenji , Kasai Daisuke , Nakamura Masaya , Ohara Seiji , Katayama Yoshihiro , Fukuda Masao , Masai Eiji
Published: June 2009

Degradation of arylglycerol-β-aryl ether is the most important process in bacterial lignin catabolism.
Sphingobium
sp. strain SYK-6 degrades guaiacylglycerol-β-guaiacyl ether (GGE) to α-(2-methoxyphenoxy)-β-hydroxypropiovanillone (MPHPV), and then the ether linkage of MPHPV is cleaved to generate α-glutathionyl-β-hydroxypropiovanillone (GS-HPV) and guaiacol. We have characterized three enantioselective glutathione
S
-transferase genes, including two genes that are involved in the ether cleavage of two enantiomers of MPHPV and one gene that is involved in the elimination of glutathione from a GS-HPV enantiomer. However, the first step in the degradation of four different GGE stereoisomers has not been characterized. In this study, three alcohol dehydrogenase genes,
ligL
,
ligN
, and
ligO
, which conferred GGE transformation activity in
Escherichia coli
, were isolated from SYK-6 and characterized, in addition to the previously cloned
ligD
gene. The levels of amino acid sequence identity of the four GGE dehydrogenases, which belong to the short-chain dehydrogenase/reductase family, ranged from 32% to 39%. Each gene was expressed in
E. coli
, and the stereospecificities of the gene products with the four GGE stereoisomers were determined by using chiral high-performance liquid chromatography with recently synthesized authentic enantiopure GGE stereoisomers. LigD and LigO converted (α
R
,β
S
)-GGE and (α
R
,β
R
)-GGE into (β
S
)-MPHPV and (β
R
)-MPHPV, respectively, while LigL and LigN transformed (α
S
,β
R
)-GGE and (α
S
,β
S
)-GGE to (β
R
)-MPHPV and (β
S
)-MPHPV, respectively. Disruption of the genes indicated that
ligD
is essential for the degradation of (α
R
,β
S
)-GGE and (α
R
,β
R
)-GGE and that both
ligL
and
ligN
contribute to the degradation of the two other GGE stereoisomers.
Anaerobic Respiration of Elemental Sulfur and Thiosulfate by
Shewanella oneidensis
MR-1 Requires
psrA
, a Homolog of the
phsA
Gene of
Salmonella enterica
Serovar Typhimurium LT2
Authors: Burns Justin L. , DiChristina Thomas J.
Published: June 2009

Shewanella oneidensis
MR-1, a facultatively anaerobic gammaproteobacterium, respires a variety of anaerobic terminal electron acceptors, including the inorganic sulfur compounds sulfite (SO
3
2−
), thiosulfate (S
2
O
3
2−
), tetrathionate (S
4
O
6
2−
), and elemental sulfur (S
0
). The molecular mechanism of anaerobic respiration of inorganic sulfur compounds by
S. oneidensis
, however, is poorly understood. In the present study, we identified a three-gene cluster in the
S. oneidensis
genome whose translated products displayed 59 to 73% amino acid similarity to the products of
phsABC
, a gene cluster required for S
0
and S
2
O
3
2−
respiration by
Salmonella enterica
serovar Typhimurium LT2. Homologs of
phsA
(annotated as
psrA
) were identified in the genomes of
Shewanella
strains that reduce S
0
and S
2
O
3
2−
yet were missing from the genomes of
Shewanella
strains unable to reduce these electron acceptors. A new suicide vector was constructed and used to generate a markerless, in-frame deletion of
psrA
, the gene encoding the putative thiosulfate reductase. The
psrA
deletion mutant (PSRA1) retained expression of downstream genes
psrB
and
psrC
but was unable to respire S
0
or S
2
O
3
2−
as the terminal electron acceptor. Based on these results, we postulate that PsrA functions as the main subunit of the
S. oneidensis
S
2
O
3
2−
terminal reductase whose end products (sulfide [HS
−
] or SO
3
2−
) participate in an intraspecies sulfur cycle that drives S
0
respiration.
Controlled Gene Expression in the Plant Pathogen
Cryphonectria parasitica
by Use of a Copper-Responsive Element
Authors: Willyerd Karyn L. , Kemp Amanda M. , Dawe Angus L.
Published: June 2009

We have developed a tool for controlled expression of heterologous or ectopic genes in the chestnut pathogen
Cryphonectria parasitica
using the promoter region from a putative copper-regulated transporter gene. In addition, we have found that expression control via this system is not affected by the virulence-attenuating hypovirus CHV1-EP713.
Genetic Determinants of Symptoms on Viral DNA Satellites
Authors: Ding Chenjun , Qing Ling , Li Zhenghe , Liu Yi , Qian Yajuan , Zhou Xueping
Published: June 2009

Begomovirus-DNA-β disease complexes induce different symptom phenotypes in their hosts. To investigate the genetic determinants of the phenotypic differences,
Nicotiana
spp. and tomato plants were inoculated with infectious clones of
Tobacco curly shoot virus
(TbCSV)/TbCSV DNA-β (TbCSB) and
Tomato yellow leaf curl China virus
(TYLCCNV)/TYLCCNV DNA-β (TYLCCNB) pseudorecombinants and showed that TYLCCNB induced characteristic vein-thickening and enation symptoms, while TbCSB only slightly exacerbated the leaf-curling symptoms, regardless of the helper virus being used. The roles of DNA-β-encoded βC1 and a 430-nucleotide fragment containing the A-rich region and the putative βC1 promoter region of the
βC1
gene (referred to as AP) in symptom development were further investigated by constructing hybrid satellites in which the βC1 coding region or AP was exchanged between the two satellite molecules. A TYLCCNB hybrid with TbCSB βC1 lost the ability to elicit the vein-thickening and enation phenotypes. TbCSB hybrids containing the TYLCCNB βC1 or AP fragment failed to induce the characteristic vein thickening and enations. A TYLCCNB hybrid having the TbCSB AP fragment produced the enations, but the number of enations was less and their sizes were reduced. Differently from the phloem-specific pattern of the TYLCCNB promoter, a full-length fragment upstream of the TbCSB
βC1
gene confers a constitutive β-glucuronidase expression pattern in transgenic tobacco plants. The above results indicate that the DNA-β-encoded βC1 protein is the symptom determinant, but the promoter of the
βC1
gene has influence on symptom production.
Role of P450 Monooxygenases in the Degradation of the Endocrine-Disrupting Chemical Nonylphenol by the White Rot Fungus
Phanerochaete chrysosporium
Authors: Subramanian Venkataramanan , Yadav Jagjit S.
Published: June 2009

The white rot fungus
Phanerochaete chrysosporium
extensively degraded the endocrine disruptor chemical nonylphenol (NP; 100% of 100 ppm) in both nutrient-limited cultures and nutrient-sufficient cultures. The P450 enzyme inhibitor piperonyl butoxide caused significant inhibition (∼75%) of the degradation activity in nutrient-rich malt extract (ME) cultures but no inhibition in defined low-nitrogen (LN) cultures, indicating an essential role of P450 monooxygenase(s) in NP degradation under nutrient-rich conditions. A genome-wide analysis using our custom-designed P450 microarray revealed significant induction of multiple P450 monooxygenase genes by NP: 18 genes were induced (2- to 195-fold) under nutrient-rich conditions, 17 genes were induced (2- to 6-fold) in LN cultures, and 3 were induced under both nutrient-rich and LN conditions. The P450 genes Pff 311b (corresponding to protein identification number [ID] 5852) and Pff 4a (protein ID 5001) showed extraordinarily high levels of induction (195- and 167-fold, respectively) in ME cultures. The P450 oxidoreductase (
POR
), glutathione
S
-transferase (
gst
), and cellulose metabolism genes were also induced in ME cultures. In contrast, certain metabolic genes, such as five of the peroxidase genes, showed partial downregulation by NP. This study provides the first evidence for the involvement of P450 enzymes in NP degradation by a white rot fungus and the first genome-wide identification of specific P450 genes responsive to an environmentally significant toxicant.
Innate Immune Defenses Induced by CpG Do Not Promote Vaccine-Induced Protection against Foot-and-Mouth Disease Virus in Pigs
Authors: Alves M. P. , Guzylack-Piriou L. , Juillard V. , Audonnet J.-C. , Doel T. , Dawson H. , Golde W. T. , Gerber H. , Peduto N. , McCullough K. C. , Summerfield A.
Published: June 2009

Emergency vaccination as part of the control strategies against foot-and-mouth disease virus (FMDV) has the potential to limit virus spread and reduce large-scale culling. To reduce the time between vaccination and the onset of immunity, immunostimulatory CpG was tested for its capacity to promote early protection against FMDV challenge in pigs. To this end, CpG 2142, an efficient inducer of alpha interferon, was injected intramuscularly. Increased transcription of Mx1, OAS, and IRF-7 was identified as a sensitive measurement of CpG-induced innate immunity, with increased levels detectable to at least 4 days after injection of CpG formulated with Emulsigen. Despite this, CpG combined with an FMD vaccine did not promote protection. Pigs vaccinated 2 days before challenge had disease development, which was at least as acute as that of unvaccinated controls. All pigs vaccinated 7 days before challenge were protected without a noticeable effect of CpG. In summary, our results demonstrate the caution required when translating findings from mouse models to natural hosts of FMDV.
Production of Extracellular Polysaccharides by
CAP
Mutants of
Cryptococcus neoformans
Authors: Grijpstra Jan , Gerwig Gerrit J. , Wösten Han , Kamerling Johannis P. , de Cock Hans
Published: June 2009

The human pathogen
Cryptococcus neoformans
causes meningoencephalitis. The polysaccharide capsule is one of the main virulence factors and consists of two distinct polysaccharides, glucuronoxylomannan (GXM) and galactoxylomannan (GalXM). How capsular polysaccharides are synthesized, transported, and assembled is largely unknown. Previously, it was shown that mutations in the
CAP10
,
CAP59
,
CAP60
, and
CAP64
genes result in an acapsular phenotype. Here, it is shown that these acapsular mutants do secrete GalXM and GXM-like polymers. GXM and GalXM antibodies specifically reacted with whole cells and the growth medium of the wild type and
CAP
mutants, indicating that the capsule polysaccharides adhere to the cell wall and are shed into the environment. These polysaccharides were purified from the medium, either with or without anion-exchange chromatography. Monosaccharide analysis of polysaccharide fractions by gas-liquid chromatography/mass spectrometry showed that wild-type cells secrete both GalXM and GXM. The
CAP
mutants, on the other hand, were shown to secrete GalXM and GXM-like polymers. Notably, the GalXM polymers were shown to contain glucuronic acid. One-dimensional
1
H nuclear magnetic resonance confirmed that the
CAP
mutants secrete GalXM and also showed the presence of O-acetylated polymers. This is the first time it is shown that
CAP
mutants secrete GXM-like polymers in addition to GalXM. The small amount of this GXM-like polymer, 1 to 5% of the total amount of secreted polysaccharides, may explain the acapsular phenotype.