bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of the granzyme B inhibitor proteinase inhibitor 9 (PI-9) by activation of lymphocytes and monocytes in vitro and by Epstein–Barr virus and bacterial infection
Authors: Classen C F , Bird P I , Debatin K-M 
Published: January 2006

Summary
Proteinase inhibitor 9 (PI-9) is an intracellular serpin expressed in lymphocytes and monocyte-derived cells. It is the only known endogenous natural antagonist of granzyme B (GrB), and its proposed function is protection of cells from misdirected GrB. We have studied the regulation of PI-9 in primary peripheral blood mononuclear cells (PBMCs) following ex-vivo stimulation, and in PBMCs from patients suffering from viral or bacterial infections. By intracellular flow cytometry, we found identical PI-9 expression in all lymphocyte subsets, lower levels in monocytes and none in granulocytes. PI-9 was stable for 48 h in the presence of cycloheximide, indicating slow protein turnover. Incubation of PBMCs with several stimuli including lipopolysaccharide (LPS) led to up-regulation in the monocyte, but not the lymphocyte fraction, within 48 h, inhibitable by the NF-κB inhibitor pyrrolidin dithiocarbamate (PTDC). Up-regulation of PI-9 was observed in lymphocytes and monocytes of patients with acute Epstein–Barr virus (EBV), but not bacterial infection. Preterm infants had similar PI-9 expression as adults in monocytes, but lower in lymphocytes, decreasing during bacterial infection. Taken together, our data indicate that PI-9 is rapidly up-regulated upon stimulation of monocytes, but not lymphocytes. By protecting monocytes and macrophages from misdirected GrB in the inflammatory process, PI-9 might be involved in the regulation of antigen presentation.
Allelopathic effect of the aquatic macrophyte, Stratiotes aloides, on natural phytoplankton
Authors: MULDERIJ GABI , SMOLDERS ALFONS J. P. , VAN DONK ELLEN 
Published: January 2006

Summary1. A survey of different Dutch Stratiotes stands showed that the density of phytoplankton (except cyanobacteria) was always higher outside S. aloides than between the rosettes of S. aloides. Analyses of water samples revealed that nutrient limitation was unlikely to have caused the lower phytoplankton biomass in the vicinity of S. aloides.2. An in situ incubation experiment in the Danube Delta, Romania, indicated allelopathic activity against phytoplankton in S. aloides stands. The growth rate of natural phytoplankton populations exposed to water from S. aloides stands was significantly lower than that of populations that had not been in contact with S. aloides exudates.3. A laboratory microcosm experiment showed a significantly lower phytoplankton biomass in treatments with S. aloides exudates. Nutrient concentrations and the light intensity were high enough that the lower phytoplankton biomass could not be explained by nutrient or light limitation.
Phylogeographic patterns of host‐race evolution in Tephritis conura (Diptera: Tephritidae)
Authors: DIEGISSER THORSTEN , SEITZ ALFRED , JOHANNESEN JES 
Published: January 2006

AbstractHost‐race evolution is a prime candidate for sympatric speciation because host shifts must take place in the presence of both hosts. However, the geographic context in which the shift takes place may have strong allopatric or peripatric components if the primary host within a localized area is scarce or even goes extinct. Inference of the relative importance of the geographic mode of speciation may be gained from phylogeographic imprints. Here, we investigate the phylogeography of host races of the tephritid fly Tephritis conura from sympatric, parapatric and allopatric populations of Cirsium heterophyllum and Cirsium oleraceum (Asteraceae) in Europe, for addressing the age and direction, and the geographic context of host‐race formation. Haplotype networks of the host races differed significantly in molecular diversity and topology. However, host‐race haplotypes were nested within the same network, with a central haplotype H1 being the most common haplotype in both host races. C. heterophyllum flies were genetically more diverse and substructured than flies from C. oleraceum, suggesting that the latter is the derived race. The phylogeographic imprint indicates either that C. heterophyllum flies colonized C. oleraceum during range expansion or that heterophyllum flies went extinct in an area where oleraceum flies persisted (followed by re‐immigration). These imprints are in concordance with peripatric diversification, probably in the European Alps and related to the last ice age, where the host‐race diversification was largely completed before the postglacial range expansion on C. oleraceum to current areas of sympatry and parapatry with C. heterophyllum.
Dissection of a functional interaction between the DNA translocase, FtsK, and the XerD recombinase
Authors: Yates James , Zhekov Ivailo , Baker Rachel , Eklund Bjørn , Sherratt David J. , Arciszewska Lidia K. 
Published: January 2006

SummarySuccessful bacterial circular chromosome segregation requires that any dimeric chromosomes, which arise by crossing over during homologous recombination, are converted to monomers. Resolution of dimers to monomers requires the action of the XerCD site‐specific recombinase at dif in the chromosome replication terminus region. This reaction requires the DNA translocase, FtsKC, which activates dimer resolution by catalysing an ATP hydrolysis‐dependent switch in the catalytic state of the nucleoprotein recombination complex. We show that a 62‐amino‐acid fragment of FtsKC interacts directly with the XerD C‐terminus in order to stimulate the cleavage by XerD of BSN, a dif‐DNA suicide substrate containing a nick in the ‘bottom’ strand. The resulting recombinase–DNA covalent complex can undergo strand exchange with intact duplex dif in the absence of ATP. FtsKC‐mediated stimulation of BSN cleavage by XerD requires synaptic complex formation. Mutational impairment of the XerD–FtsKC interaction leads to reduction in the in vitro stimulation of BSN cleavage by XerD and a concomitant deficiency in the resolution of chromosomal dimers at dif in vivo, although other XerD functions are not affected.
Imaging OmpR localization in Escherichia coli
Authors: Batchelor Eric , Goulian Mark 
Published: January 2006

SummaryWe have used a fusion of GFP to the response regulator OmpR to image the spatial distribution of OmpR in live cells of Escherichia coli. We observed foci of increased OmpR–GFP fluorescence that appear to be due to interactions with the histidine kinase EnvZ. We also observed colocalization of OmpR–GFP with clusters of plasmids carrying OmpR binding sites, which enabled us to develop a simple method for imaging the binding of OmpR to DNA in live cells. We used the peak fluorescence intensity within cells to quantify the extent of OmpR–GFP localization either due to interactions with EnvZ or due to binding DNA. With these assays we compared the effects of osmolarity and procaine, both of which are believed to modulate EnvZ activity. Our results suggest that, at least under our growth conditions, procaine activates EnvZ–OmpR signalling whereas osmolarity has, at best, a weak effect on the EnvZ–OmpR system.
Organic anion exudation by ectomycorrhizal fungi and Pinus sylvestris in response to nutrient deficiencies
Authors: Van Schöll Laura , Hoffland Ellis , Van Breemen Nico 
Published: January 2006

Summary

Low molecular weight organic anions (LMWOA) can enhance weathering of mineral grains. We tested the hypothesis that ectomycorrhizal (EcM) fungi and tree seedlings increase their exudation of LMWOA when supply of magnesium, potassium and phosphorus is low to enhance the mobilization of Mg, K and P from mineral grains.
Ectomycorrhizal fungi and Pinus sylvestris seedlings were cultured in symbiosis and in isolation on glass beads with nutrient solution or with sand as a rooting medium, with a complete nutrient supply or with Mg, K, P or N in low supply. Concentrations of all dicarboxylic LMWOA in the rooting medium were measured.
Nonmycorrhizal seedlings released predominantly malonate. Colonization with Hebeloma longicaudum decreased the amount of organic anions exuded, whereas Paxillus involutus and Piloderma croceum increased the concentration of oxalate but not the total amount of LMWOA. Phosphorus deficiency increased the concentration of LMWOA by nonmycorrhizal and EcM seedlings. Magnesium deficiency increased the concentration of oxalate by nonmycorrhizal and EcM seedlings, but not the concentration of total LMWOA. Paxillus involutus grown in pure culture responded differently to low nutrient supply compared with symbiotic growth.
Ectomycorrhizal fungi did not increase the total concentration of LMWOA compared with nonmycorrhizal seedlings but, depending on the fungal species, they affected the type of LMWOA found.
Influencing consumer purchase likelihood of organic food
Authors: Gifford Katie , Bernard John C. 
Published: January 2006

AbstractOrganic food is a fast‐growing niche market in the US. Information in the marketplace tends to promote organic by describing either the potential benefits from organic methods (positive framing) or the potential negative consequences of conventional agriculture (negative framing). For this research, a survey was designed to test the effect of positive and negative framing on the self‐reported change in purchase likelihood of organic food. Respondents were asked to directly evaluate whether the information in the survey made them more or less likely to purchase organic food, or if there was no change. Over 40% of the respondents reported greater likelihood of purchasing organic as a result of the survey information, and less than 4% said they would be less likely to buy it. Tobit regression results revealed that positive framing and perceived risk from conventional agricultural methods increased the influence of the survey. African‐Americans and those with more prior knowledge of organic methods reported less influence from the survey. Overall, information and knowledge variables had more effect on the impact of the survey than demographic variables.
The positive allosteric modulator GS39783 enhances GABAB receptor‐mediated inhibition of cyclic AMP formation in rat striatum in vivo
Authors: Gjoni Tina , Desrayaud Sandrine , Imobersteg Stefan , Urwyler Stephan 
Published: January 2006

AbstractWe studied the effects of the positive allosteric modulator GS39783 on GABAB receptors at a biochemical level in vivo. Changes in extracellular levels of cyclic AMP following GABAB receptor activation were monitored in the striatum of freely moving rats using microdialysis. Locally applied GABAB agonist R(–)‐baclofen inhibited cyclic AMP formation stimulated by a water‐soluble forskolin analogue in a concentration‐dependent manner (EC50 7.3 µm, maximal inhibition 40%). The selective GABAB antagonist CGP56999 reversed R(–)‐baclofen‐induced cyclic AMP inhibition to control levels, but not higher. Orally applied GS39783 lacked effects on its own but, together with a threshold concentration of R(–)‐baclofen (1 µm), significantly decreased cyclic AMP formation in a dose‐dependent fashion. Effects of GS39783 were revoked with CGP56999, showing dependence on GABAB receptor activation and suggesting allosteric modulation as a mechanism of action in vivo. Administered with a maximally active dose of R(–)‐baclofen, GS39783 failed to further inhibit cyclic AMP formation. The data obtained with CGP56999 and the lack of effect of GS39783 alone suggest that there is no detectable endogenous activation of GABAB receptors controlling cyclic AMP formation in rat striatum. To our knowledge, these results provide the first biochemical demonstration of in vivo activity of a G protein‐coupled receptor‐positive allosteric modulator.
Homocysteine‐induced endoplasmic reticulum protein (Herp) is up‐regulated in sporadic inclusion‐body myositis and in endoplasmic reticulum stress‐induced cultured human muscle fibers
Authors: Nogalska Anna , Engel W. King , McFerrin Janis , Kokame Koichi , Komano Hiroto , Askanas Valerie 
Published: January 2006

AbstractHerp is a stress‐response protein localized in the endoplasmic reticulum (ER) membrane. Herp was proposed to improve ER‐folding, decrease ER protein load, and participate in ER‐associated degradation (ERAD). Intra‐muscle‐fiber ubiquitinated multiprotein‐aggregates containing, among other proteins, either amyloid‐β (Aβ) or phosphorylated tau are characteristic of sporadic inclusion‐body myositis (s‐IBM). ER stress and proteasome inhibition appear to play a role in s‐IBM pathogenesis. We have now studied Herp in s‐IBM muscle fibers and in ER‐stress‐induced or proteasome‐inhibited cultured human muscle fibers. In s‐IBM muscle fibers: (i) Herp was strongly immunoreactive in the form of aggregates, which co‐localized with Aβ, GRP78, and β2 proteasome subunit; (ii) Herp mRNA and protein were increased. In ER‐stress‐induced cultured human muscle fibers: (i) Herp immunoreactivity was diffusely increased; (ii) Herp mRNA and protein were increased. In proteasome‐inhibited cultured human muscle fibers: (i) Herp immunoreactivity was in the form of aggregates; (ii) Herp protein was increased, but its mRNA was not. Accordingly, in s‐IBM muscle fibers: (i) increase of Herp might be due to both ER‐stress and proteasome inhibition; (ii) co‐localization of Herp with Aβ, proteasome, and ER‐chaperone GRP78 could reflect its possible role in processing and degradation of cytotoxic proteins in ER.
INTANGIBLE ASSETS, BOOK‐TO‐MARKET, AND COMMON STOCK RETURNS
Authors: Nelson James M. 
Published: January 2006

AbstractI examine two anomalies where the Fama and French three‐factor model fails to adequately explain monthly industry and index returns. Both anomalies are consistent with a bad model problem where the book‐to‐market factor introduces a negative bias in the intercepts. I propose the intangibles model as an alternative where the three‐factor model is known to have difficulty. This alternative model, which replaces the book‐to‐market factor with zero investment portfolio returns based on prior investments in intangible assets, is well specified in random samples, has comparable power, and fully explains both anomalies.
SECURITIES PRICE EFFECTS OF UNIONIZATION LEGISLATION
Authors: Naiker Vic , Navissi Farshid 
Published: January 2006

AbstractPrior studies document that firms experience negative stock price effects in response to unionization. We study the economic effects of a radical change in unionization legislation in New Zealand and hypothesize that the stock price effect of unionization is a function of prior unionization status of firms. We provide evidence that legislative events that increase the likelihood of introducing more stringent legislation do not affect stock prices of high‐unionized firms, whereas low‐unionized firms are affected negatively and significantly. Legislative events that signal less stringent unionization legislation result in significant stock price increases for all firms.
Multidrug resistance 1 genotype and disposition of budesonide in early primary biliary cirrhosis
Authors: Dilger Karin , Cascorbi Ingolf , Grünhage Frank , Hohenester Simon , Sauerbruch Tilman , Beuers Ulrich 
Published: January 2006

Abstract: Background: Budesonide, which is a dual substrate of P‐glycoprotein, the product of the multidrug resistance 1 (MDR1) gene, and cytochrome P450 3A (CYP3A) has been proposed for treatment of early primary biliary cirrhosis (PBC). Recently, MDR1 gene polymorphisms have been discussed as a potential cause of glucocorticoid resistance. We tested the hypothesis that MDR1 gene polymorphisms affect absorption of oral budesonide.Methods: In 21 patients with histologically proven early‐stage (I/II) PBC and nine healthy subjects, we evaluated the impact of MDR1 single nucleotide polymorphisms (2677G>T,A and 3435C>T) on disposition of a single oral dose of 3 mg budesonide. CYP3A5 gene polymorphisms (6986A>G) were analyzed in parallel.Results: In MDR1 2677 GG and 3435 CC genotypes, absorption and elimination of budesonide were not significantly different from those in corresponding homozygous variants. Peak plasma levels and areas under the plasma concentration time curves (AUC) of budesonide were not lower in MDR1 3435 CC with putatively high intestinal expression of P‐glycoprotein than in MDR1 3435 TT. Interestingly, in two CYP3A5*1/*3 carriers with high enzyme activity, lower AUC was noted than in 28 CYP3A5*3/*3 carriers with a deficient enzyme.Conclusion: Common MDR1 gene polymorphisms do not affect disposition of budesonide in early PBC.
Adnexal masses in pregnancy: A 5‐year review
Authors: KUMARI Ibha , KAUR Shanujeet , MOHAN Harsh , HURIA Anju 
Published: January 2006

AbstractA retrospective analysis of all pregnant women who had an adnexal mass surgically resected at the Government Medical College and Hospital, Chandigarh, over a 5‐year period found an incidence of 20 in 16 260 deliveries during the study period. The most frequent complication was torsion (25% of the cases) and the majority of cases occurred in the first trimester of pregnancy. Two of the women had malignant ovarian tumours. There was no difference in gestational age at delivery or birth weight in patients undergoing emergency surgery versus elective surgery.
The Dynamics of Incrementalism: Subsystems, Politics, and Public Lands
Authors: Wood Robert S. 
Published: January 2006

A host of research has been produced in the decade since Baumgartner and Jones’ theory of punctuated equilibrium first drew attention to the dynamics of policy change over time. Much of this research follows a topic across time, highlighting the shift from negative to positive feedback as challengers push an issue from subsystem to institutional level. Far less attention has been paid to the periods between major punctuations, neglecting key questions about whether incremental periods reflect an absence of challengers or the successful defense of established subsystem interests.This research is a comparison of policy change across two segments of environmental policy. The breakup of the timber subsystem was a clear victory for environmentalists, yet these same actors have been largely unsuccessful at dislodging established grazing interests. These findings highlight the strategic value of venue shifting for bypassing entrenched interests and illustrate the potential for successful challenges to occur in judicial venues.
Role of the Extended α4 Domain of
Staphylococcus aureus
Gyrase A Protein in Determining Low Sensitivity to Quinolones
Authors: Strahilevitz Jacob , Robicsek Ari , Hooper David C. 
Published: January 2006

ABSTRACT

Fluoroquinolones target two bacterial type II topoisomerases, DNA gyrase and topoisomerase IV. Acquired resistance to quinolones occurs stepwise, with the first mutation occurring in the more sensitive target enzyme. To limit the emergence of resistance, quinolones should ideally possess dual activities against the two enzymes. For reasons that are as yet unclear,
Staphylococcus aureus
gyrase is less sensitive to quinolones than topoisomerase IV, counter to its greater sensitivity in
Escherichia coli
, thereby limiting the use of quinolones for the treatment of staphylococcal infections. Mutations in the α4-helix domain of the GyrA subunit of gyrase are important in determining quinolone resistance. We replaced an extended region encompassing the α4 domain in the
E. coli
GyrA protein with its homolog in
S. aureus
and tested for its ability to complement a thermosensitive gyrase and its catalytic and noncatalytic properties. Purified gyrase reconstituted with chimeric GyrA was more resistant to ciprofloxacin than wild-type gyrase at both inhibition of catalytic activity and stimulation of cleavage complexes, and this difference was more apparent in the presence of K
+
-glutamate. The chimeric GyrA subunit was able to complement thermosensitive gyrase, similar to wild-type GyrA. Without supplemental K
+
-glutamate the MICs of ciprofloxacin for thermosensitive
E. coli
complemented with chimeric DNA gyrase were equal to those for
E. coli
complemented with wild-type gyrase but were twofold higher in the presence of K
+
-glutamate. Our findings suggest that the extended α4 domain of
S. aureus
GyrA is responsible, at least in part, for the increased resistance of
S. aureus
gyrase to quinolones and that this effect is modulated by K
+
-glutamate.
Emergence of DHA-1-Producing
Klebsiella
spp. in the Parisian Region: Genetic Organization of the
ampC
and
ampR
Genes Originating from
Morganella morganii
Authors: Verdet Charlotte , Benzerara Yahia , Gautier Valérie , Adam Olivier , Ould-Hocine Zahia , Arlet Guillaume 
Published: January 2006

ABSTRACT

Eleven
Klebsiella pneumoniae
clinical isolates and one
Klebsiella oxytoca
clinical isolate showing various pulsed-field gel electrophoresis types and producing an inducible DHA-1 class C β-lactamase were isolated in the Parisian region between 1998 and 2003. The aim of this study was to compare the genetic organization of the
bla
DHA-1
genes in this collection of clinical isolates. In four isolates, the
Morganella morganii
-derived genomic region containing
bla
DHA-1
was inserted in an entire complex
sul1
-type integron, including a region common to In6-In7 (CR1), as previously described in a
bla
DHA-1
-producing
Salmonella enterica
serovar Enteritidis KF92 isolate from Saudi Arabia in 1992. Different gene cassette arrays were characterized in each of these integrons. In two of them, an additional 10-kb fragment was inserted between the CR1 and the
M. morganii
-derived region and was similar to the
sap
(ABC transporter family) and
psp
(phage shock protein) operons originated from
Salmonella enterica
serovar Typhimurium. The length of the
M. morganii
region was variable, suggesting that several independent recombination events have occurred and that open reading frame
orf513
encodes a recombinase involved in the mobilization of the resistance genes. The genetic organization of
bla
DHA-1
was identical in the eight other isolates. This structure is likely derived from a complex integron following the insertion of IS
26
, leading to the deletion of the first part of integron. The horizontal transfer of one plasmid carrying that truncated integron was shown for seven of these isolates.
Linezolid in Prophylaxis against Experimental Aortic Valve Endocarditis Due to
Streptococcus oralis
or
Enterococcus faecalis
Authors: Athanassopoulos George , Pefanis Angelos , Sakka Vissaria , Iliopoulos Dimitrios , Perrea Despina , Giamarellou Helen 
Published: January 2006

ABSTRACT

There are no experimental studies regarding the prophylactic efficacy of linezolid against infective endocarditis. Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits by the insertion of a polyethylene catheter. Twenty-four hours later, animals were randomly assigned to a control group, and groups receiving either ampicillin (two doses of 40 mg/kg of body weight each, given intravenously, 2 h apart) or linezolid (a single per os dose of 75 mg/kg). The first dose of ampicillin and the single dose of linezolid were administered 0.5 and 1 h, respectively, prior to the intravenous inoculation of ∼10
7
CFU of
Streptococcus oralis
or
Enterococcus faecalis
. Linezolid peak levels in rabbit serum were similar to the peak serum levels in humans following a 600-mg oral dose of linezolid. Linezolid prevented endocarditis in 87% of
S. oralis
-challenged rabbits (
P
< 0.001 versus controls;
P
= 0.026 versus ampicillin). In rabbits challenged with
E. faecalis
, linezolid prevented endocarditis in 73% (
P
= 0.003 versus controls;
P
= 0.049 versus ampicillin). Ampicillin prevented endocarditis due to
S. oralis
or due to
E. faecalis
in 47% (
P
= 0.005 versus controls) and in 30% (
P
= not significant versus controls) of the challenged animals, respectively. In conclusion, linezolid was effective as prophylaxis against endocarditis caused by a strain of
S. oralis
and to a lesser degree against that caused by a strain of
E. faecalis
. Its prophylactic efficacy was superior to that of ampicillin.