bluuebunny/crossref_metadata_2025_split huggingface dataset:
Timing of placental delivery to prevent post‐partum haemorrhage: Lessons learned from an abandoned randomised clinical trial
Authors: MAGANN Everett F. , DOHERTY Dorota A. , BRIERY Christian M. , NIEDERHAUSER Amy , MORRISON John C. 
Published: November 2006

AbstractIt has been recognised that, if the length of the third stage of labour exceeds 30 min, then there is an increased risk of a post‐partum haemorrhage. Recent information has suggested that 18 min is the optimal time for removal of the undelivered placenta to prevent a post‐partum haemorrhage. A randomised trial comparing 20 vs. 30 min was stopped after an interim analysis because only eight of 1607 patients’ placentas had not delivered by 20 min. A third stage of labour that exceeded 10 min was observed to be significantly correlated with an increased risk of post‐partum haemorrhage.
A new type of long gamma-ray burst
Authors: King Andrew , Olsson Emma , Davies Melvyn B. 
Published: November 2006

Abstract
We consider gamma-ray bursts (GRBs) produced by the merger of a massive white dwarf with a neutron star. We show that these are likely to produce long-duration GRBs, in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation, and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions, and could have any type of host galaxy. Thus a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that our proposed class may be an important contributor to the observed GRB rate.
Recombinant activated factor VII for trauma patients
Authors: DUTTON RICHARD P. 
Published: November 2006

SUMMARYThe use of recombinant activated factor VII (rFVIIa) in trauma patients is an exciting application because hemorrhage and coagulopathy play prominent roles both in the syndrome of severe hemorrhagic shock and in severe traumatic brain injury (TBI). Anecdotal use of rFVIIa in non‐hemophilic trauma patients extends back to 1999, and experience at individual institutions is now in the hundreds of cases. Efficacy in controlling traumatic coagulopathy approaches 80%, with long‐term survival of about half of the patients treated. There have been few reports of inappropriate thrombotic events in trauma patients. A single prospective randomized study of rFVIIa in victims of hemorrhagic shock has been completed, with some favorable results. Further trials in hemorrhagic shock are underway in both European and American trauma centers, while a trial in TBI patients will begin within the coming year.
Estimation of Microbial Contamination of Food from Prevalence and Concentration Data: Application to
Listeria monocytogenes
in Fresh Vegetables
Authors: Crépet Amélie , Albert Isabelle , Dervin Catherine , Carlin Frédéric 
Published: November 2006

ABSTRACT

A normal distribution and a mixture model of two normal distributions in a Bayesian approach using prevalence and concentration data were used to establish the distribution of contamination of the food-borne pathogenic bacteria
Listeria monocytogenes
in unprocessed and minimally processed fresh vegetables. A total of 165 prevalence studies, including 15 studies with concentration data, were taken from the scientific literature and from technical reports and used for statistical analysis. The predicted mean of the normal distribution of the logarithms of viable
L. monocytogenes
per gram of fresh vegetables was −2.63 log viable
L. monocytogenes
organisms/g, and its standard deviation was 1.48 log viable
L. monocytogenes
organisms/g. These values were determined by considering one contaminated sample in prevalence studies in which samples are in fact negative. This deliberate overestimation is necessary to complete calculations. With the mixture model, the predicted mean of the distribution of the logarithm of viable
L. monocytogenes
per gram of fresh vegetables was −3.38 log viable
L. monocytogenes
organisms/g and its standard deviation was 1.46 log viable
L. monocytogenes
organisms/g. The probabilities of fresh unprocessed and minimally processed vegetables being contaminated with concentrations higher than 1, 2, and 3 log viable
L. monocytogenes
organisms/g were 1.44, 0.63, and 0.17%, respectively. Introducing a sensitivity rate of 80 or 95% in the mixture model had a small effect on the estimation of the contamination. In contrast, introducing a low sensitivity rate (40%) resulted in marked differences, especially for high percentiles. There was a significantly lower estimation of contamination in the papers and reports of 2000 to 2005 than in those of 1988 to 1999 and a lower estimation of contamination of leafy salads than that of sprouts and other vegetables. The interest of the mixture model for the estimation of microbial contamination is discussed.
Acid Tolerance of
Streptococcus macedonicus
as Assessed by Flow Cytometry and Single-Cell Sorting
Authors: Papadimitriou Konstantinos , Pratsinis Harris , Nebe-von-Caron Gerhard , Kletsas Dimitris , Tsakalidou Effie 
Published: November 2006

ABSTRACT

An in situ flow cytometric viability assay employing carboxyfluorescein diacetate and propidium iodide was used to identify
Streptococcus macedonicus
acid tolerance phenotypes. The logarithmic-phase acid tolerance response (L-ATR) was evident when cells were (i) left to autoacidify unbuffered medium, (ii) transiently exposed to nonlethal acidic pH, or (iii) systematically grown under suboptimal acidic conditions (acid habituation). Stationary-phase ATR was also detected; this phenotype was gradually degenerated while cells resided at this phase. Single-cell analysis of
S. macedonicus
during induction of L-ATR revealed heterogeneity in both the ability and the rate of tolerance acquisition within clonal populations. L-ATR was found to be partially dependent on de novo protein synthesis and compositional changes of the cell envelope. Interestingly, acid-habituated cells were interlaced in lengthier chains and exhibited an irregular pattern of active peptidoglycan biosynthesis sites when probed with BODIPY FL vancomycin. L-ATR caused cells to retain their membrane potential after lethal challenge, as judged by ratiometric analysis with oxonol [DiBAC
4
(3)]. Furthermore, F-ATPase was important during the induction of L-ATR, but in the case of a fully launched response, inhibition of F-ATPase affected acid resistance only partially. Activities of both F-ATPase and the glucose-specific phosphoenolpyruvate-dependent phosphotransferase system were increased after L-ATR induction, distinguishing
S. macedonicus
from oral streptococci. Finally, the in situ viability assessment was compared to medium-based recovery after single-cell sorting, revealing that the culturability of subpopulations with identical fluorescence characteristics is dependent on the treatments imposed to the cells prior to acid challenge.
Cryptococcus neoformans
Can Utilize the Bacterial Melanin Precursor Homogentisic Acid for Fungal Melanogenesis
Authors: Frases Susana , Salazar Angela , Dadachova Ekaterina , Casadevall Arturo 
Published: November 2006

ABSTRACT

Cryptococcus neoformans
melanizes in the environment and in mammalian tissues, but the process of melanization in either venue is mysterious given that this microbe produces melanin only from exogenous substrates. Understanding the process of melanization is important because melanization is believed to protect against various stresses in the environment, including UV radiation, and pigment production is associated with virulence. Melanization in
C. neoformans
requires the availability of diphenolic precursors. In contrast, many bacteria synthesize melanin from homogentisic acid (HGA). We report that
C. neoformans
strains representing all four serotypes can produce a brown pigment from HGA. The brown pigment was acid resistant and had the electron paramagnetic resonance spectrum of a stable free radical, qualities that identified it as a melanin. Melanin “ghost”-like particles obtained from pigmented
C. neoformans
cells were hydrophobic, fluorescent under a variety of irradiation wavelengths, negatively charged, insoluble in organic solvents and alcohols, resistant to degradation by strong acids, and vulnerable to bleaching. HGA melanization was laccase dependent and repressed by high concentrations of glucose. The ability of
C. neoformans
to utilize a bacterial melanin precursor compound suggests a new substrate source for melanization in the environment.
Involvement of
Pseudomonas aeruginosa
Rhodanese in Protection from Cyanide Toxicity
Authors: Cipollone Rita , Frangipani Emanuela , Tiburzi Federica , Imperi Francesco , Ascenzi Paolo , Visca Paolo 
Published: November 2006

ABSTRACT

Cyanide is a serious environmental pollutant and a biocontrol metabolite in plant growth-promoting
Pseudomonas
species. Here we report on the presence of multiple sulfurtransferases in the cyanogenic bacterium
Pseudomonas aeruginosa
PAO1 and investigate in detail RhdA, a thiosulfate:cyanide sulfurtransferase (rhodanese) which converts cyanide to less toxic thiocyanate. RhdA is a cytoplasmic enzyme acting as the principal rhodanese in
P. aeruginosa
. The
rhdA
gene forms a transcriptional unit with the PA4955 and
psd
genes and is controlled by two promoters located upstream of PA4955 and
rhdA
. Both promoters direct constitutive RhdA expression and show similar patterns of activity, involving moderate down-regulation at the stationary phase or in the presence of exogenous cyanide. We previously observed that RhdA overproduction protects
Escherichia coli
against cyanide toxicity, and here we show that physiological RhdA levels contribute to
P. aeruginosa
survival under cyanogenic conditions. The growth of a Δ
rhdA
mutant is impaired under cyanogenic conditions and fully restored upon complementation with
rhdA
. Wild-type
P. aeruginosa
outcompetes the Δ
rhdA
mutant in cyanogenic coculture assays. Hence, RhdA could be regarded as an effector of
P. aeruginosa
intrinsic resistance to cyanide, insofar as it provides the bacterium with a defense mechanism against endogenous cyanide toxicity, in addition to cyanide-resistant respiration.
Production of Antibacterial Compounds and Biofilm Formation by
Roseobacter
Species Are Influenced by Culture Conditions
Authors: Bruhn Jesper Bartholin , Gram Lone , Belas Robert 
Published: November 2006

ABSTRACT

Bacterial communities associated with marine algae are often dominated by members of the
Roseobacter
clade, and in the present study, we describe
Roseobacter
phenotypes that may provide this group of bacteria with selective advantages when colonizing this niche. Nine of 14 members of the
Roseobacter
clade, of which half were isolated from cultures of the dinoflagellate
Pfiesteria piscicida
, produced antibacterial compounds. Many non-
Roseobacter
marine bacteria were inhibited by sterile filtered supernatants of
Silicibacter
sp. TM1040 and
Phaeobacter
(formerly
Roseobacter
) strain 27-4, which had the highest production of antibacterial compound. In contrast,
Roseobacter
strains were susceptible only when exposed to concentrated compound. The production of antibacterial compound was influenced by the growth conditions, as production was most pronounced when bacteria were grown in liquid medium under static conditions. Under these conditions,
Silicibacter
sp. TM1040 cells attached to one another, forming rosettes, as has previously been reported for
Phaeobacter
27-4. A spontaneous
Phaeobacter
27-4 mutant unable to form rosettes was also defective in biofilm formation and the production of antibacterial compound, indicating a possible link between these phenotypes. Rosette formation was observed in 8 of 14
Roseobacter
clade strains examined and was very pronounced under static growth in 5 of these strains. Attachment to surfaces and biofilm formation at the air-liquid interface by these five strains was greatly facilitated by growth conditions that favored rosette formation, and rosette-forming strains were 13 to 30 times more efficient in attaching to glass compared to strains under conditions where rosette formation was not pronounced. We hypothesize that the ability to produce antibacterial compounds that principally inhibit non-
Roseobacter
species, combined with an enhancement in biofilm formation, may give members of the
Roseobacter
clade a selective advantage and help to explain the dominance of members of this clade in association with marine algal microbiota.
Recombinant Bactericidal/Permeability-Increasing Protein rBPI21Protects against Pneumococcal Disease
Authors: Srivastava Amit , Casey Heather , Johnson Nathaniel , Levy Ofer , Malley Richard 
Published: November 2006

ABSTRACTBactericidal/permeability-increasing (BPI) protein has been shown to play an important role in innate immunity to gram-negative bacteria, by direct microbicidal as well as endotoxin-neutralizing action. Here we examined potential interactions between a recombinant 21-kDa bioactive fragment of BPI, rBPI21, and the gram-positive pathogenStreptococcus pneumoniae. rBPI21bound to pneumococci and pneumolysin (Ply) in a direct and specific fashion. We observed an enhanced inflammatory response in mouse macrophages when rBPI21was combined with killed pneumococci or supernatant from overnight growth of pneumococci. In addition, rBPI21augmented the proapoptotic activity of Ply+(but not Ply−) pneumococci in TLR4-defective murine macrophages (known to be defective also in their apoptotic response to pneumolysin) in a tumor necrosis factor alpha-dependent manner. rBPI21also enhanced the association of pneumococci with murine macrophages. In a model of invasive pneumococcal disease in TLR4-defective mice, the intranasal administration of rBPI21following intranasal inoculation of Ply+pneumococci both enhanced upper respiratory tract cell apoptosis and prolonged survival. We have thus discovered a novel interaction between pneumococcus and rBPI21, a potent antimicrobial peptide previously considered to target only gram-negative bacteria.
Characterization of the Urease Operon of
Brucella abortus
and Assessment of Its Role in Virulence of the Bacterium
Authors: Sangari Félix J. , Seoane Asunción , Rodríguez María Cruz , Agüero Jesús , García Lobo Juan M. 
Published: November 2006

ABSTRACT

Most members of the genus
Brucella
show strong urease activity. However, the role of this enzyme in the pathogenesis of
Brucella
infections is poorly understood. We isolated several Tn
5
insertion mutants deficient in urease activity from
Brucella abortus
strain 2308. The mutations of most of these mutants mapped to a 5.7-kbp DNA region essential for urease activity. Sequencing of this region, designated
ure1
, revealed the presence of seven open reading frames corresponding to the urease structural proteins (UreA, UreB, and UreC) and the accessory proteins (UreD, UreE, UreF, and UreG). In addition to the urease genes, another gene (
cobT
) was identified, and inactivation of this gene affected urease activity in
Brucella
. Subsequent analysis of the previously described sequences of the genomes of
Brucella
spp. revealed the presence of a second urease cluster,
ure2
, in all them. The
ure2
locus was apparently inactive in
B. abortus
2308. Urease-deficient mutants were used to evaluate the role of urease in
Brucella
pathogenesis. The urease-producing strains were found to be resistant in vitro to strong acid conditions in the presence of urea, while urease-negative mutants were susceptible to acid treatment. Similarly, the urease-negative mutants were killed more efficiently than the urease-producing strains during transit through the stomach. These results suggested that urease protects brucellae during their passage through the stomach when the bacteria are acquired by the oral route, which is the major route of infection in human brucellosis.
The Rab6 Effector Bicaudal D1 Associates with
Chlamydia trachomatis
Inclusions in a Biovar-Specific Manner
Authors: Moorhead A. R. , Rzomp K. A. , Scidmore M. A. 
Published: November 2006

ABSTRACT

Chlamydia
species are obligate intracellular bacteria that replicate within a membrane-bound vacuole, the inclusion, which is trafficked to the peri-Golgi region by processes that are dependent on early chlamydial gene expression. Although neither the host nor the chlamydial proteins that regulate the intracellular trafficking have been clearly defined, several enhanced green fluorescent protein (EGFP)-tagged Rab GTPases, including Rab6, are recruited to
Chlamydia trachomatis
inclusions. To further characterize the association of Rab6 with
C. trachomatis
inclusions, we examined the intracellular localization of guanine nucleotide-binding mutants of Rab6 and demonstrated that only active GTP-bound and not inactive GDP-bound EGFP-Rab6 mutants were recruited to the inclusion, suggesting that EGFP-Rab6 interacts with the inclusion via a host Rab6 effector or a chlamydial protein that mimics a Rab6 effector. Using EGFP-tagged fusion proteins, we also demonstrated that the Rab6 effector Bicaudal D1 (BICD1) localized to
C. trachomatis
inclusions in a biovar-specific manner. In addition, we demonstrated that EGFP-Rab6 and its effector EGFP-BICD1 are recruited to the inclusion in a microtubule- and Golgi apparatus-independent but chlamydial gene expression-dependent mechanism. Finally, in contrast to the Rab6-dependent Golgi apparatus localization of endogenous BICD1, EGFP-BICD1 was recruited to the inclusion by a Rab6-independent mechanism. Collectively, these data demonstrate that neither Rab6 nor BICD1 is trafficked to the inclusion via a Golgi apparatus-localized intermediate, suggesting that each protein is trafficked to the
C. trachomatis
serovar L2 inclusion by a unique, but as-yet-undefined, mechanism.
Streptococcus iniae
Capsule Impairs Phagocytic Clearance and Contributes to Virulence in Fish
Authors: Locke Jeffrey B. , Colvin Kelly M. , Datta Anup K. , Patel Silpa K. , Naidu Nandita N. , Neely Melody N. , Nizet Victor , Buchanan John T. 
Published: November 2006

ABSTRACT

Surface capsular polysaccharides play a critical role in protecting several pathogenic microbes against innate host defenses during infection. Little is known about virulence mechanisms of the fish pathogen
Streptococcus iniae
, though indirect evidence suggests that capsule could represent an important factor. The putative
S. iniae
capsule operon contains a homologue of the
cpsD
gene, which is required for capsule polymerization and export in group B
Streptococcus
and
Streptococcus pneumoniae
. To elucidate the role of capsule in the
S. iniae
infectious process, we deleted
cpsD
from the genomes of two virulent
S. iniae
strains by allelic exchange mutagenesis to generate the isogenic capsule-deficient Δ
cpsD
strains. Compared to wild-type
S. iniae
, the Δ
cpsD
mutants had a predicted reduction in buoyancy and cell surface negative charge. Transmission electron microscopy confirmed a decrease in the abundance of extracellular capsular polysaccharide. Gas-liquid chromatography-mass spectrometry analysis of the
S. iniae
extracellular polysaccharides showed the presence of
l
-fucose,
d
-mannose,
d
-galactose,
d
-glucose,
d
-glucuronic acid,
N
-acetyl-
d
-galactosamine, and
N
-acetyl-
d
-glucosamine, and all except mannose were reduced in concentration in the isogenic mutant. The Δ
cpsD
mutants were highly attenuated in vivo in a hybrid striped bass infection challenge despite being more adherent and invasive to fish epithelial cells and more resistant to cationic antimicrobial peptides than wild-type
S. iniae
. Increased susceptibility of the
S. iniae
Δ
cpsD
mutants to phagocytic killing in whole fish blood and by a fish macrophage cell line confirmed the role of capsule in virulence and highlighted its antiphagocytic function. In summary, we report a genetically defined study on the role of capsule in
S. iniae
virulence and provide preliminary analysis of
S. iniae
capsular polysaccharide sugar components.
Analysis of the Amino Acid Sequence Specificity Determinants of the Enterococcal cCF10 Sex Pheromone in Interactions with the Pheromone-Sensing Machinery
Authors: Fixen Kathryn R. , Chandler Josephine R. , Le Thinh , Kozlowicz Briana K. , Manias Dawn A. , Dunny Gary M. 
Published: November 2006

ABSTRACTThe level of expression of conjugation genes inEnterococcus faecalisstrains carrying the pheromone-responsive transferable plasmid pCF10 is determined by the ratio in the culture medium of two types of signaling peptides, a pheromone (cCF10) and an inhibitor (iCF10). Recent data have demonstrated that both peptides target the cytoplasmic receptor protein PrgX. However, the relative importance of the interaction of these peptides with the pCF10 protein PrgZ (which enhances import of cCF10) versus PrgX is not fully understood, and there is relatively little information about specific amino acid sequence determinants affecting the functional interactions of cCF10 with these proteins in vivo. To address these issues, we used a pheromone-inducible reporter gene system where various combinations of PrgX and PrgZ could be expressed in an isogenic host background to examine the biological activities of cCF10, iCF10, and variants of cCF10 isolated in a genetic screen. The results suggest that most of the amino acid sequence determinants of cCF10 pheromone activity affect interactions between the peptide and PrgX, although some sequence variants that affected peptide/PrgZ interactions were also identified. The results provide functional data to complement ongoing structural studies of PrgX and increase our understanding of the functional interactions of cCF10 and iCF10 with the pheromone-sensing machinery of pCF10.
Generalised convulsive status epilepticus: an overview
Authors: Nandhagopal R 
Published: November 2006

Abstract
Generalised convulsive status epilepticus is one of the most common emergencies encountered in clinical practice. This review discusses the recent understanding of this life-threatening condition with reference to the definition, pathophysiology, evaluation, complications, refractory status and prognosis. Besides epilepsy, other neurological and medical illnesses could be associated with status epilepticus. The goals of management and pharmacological approach are outlined, considering the available evidence. Prompt recognition and timely intervention, including pre-hospital treatment, are therapeutically beneficial. Refractory status should be managed in intensive care units under close monitoring. More evidence is needed for evolving the optimal treatment. A suitable treatment protocol would guide in avoiding the pitfalls at various points along the management pathway.
Antibiotic prescription for patients referred to a specialist breast clinic
Authors: Twine C , Gateley C A 
Published: November 2006

Abstract
Hospital referral is indicated as an emergency for breast infections not settling with oral antibiotics. Referrals to a breast clinic over a period of 6 months were assessed for prior antibiotic prescription. A total of 1078 patients were seen during this period. 91 (8%) patients had been prescribed antibiotics, 71% of which had been prescribed for non-infective conditions. Of those patients treated for infection, 42% had the wrong antibiotic prescribed. The final diagnoses for patients inappropriately prescribed antibiotics were chest wall pain in 23% and duct ectasia in 14%. Although the reasons for prescription of antibiotics are mutifactorial, careful examination of the patient will diagnose chest wall pain. Delayed prescribing may be appropriate for some patients.