bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bacterial Contamination of Stethoscope Chest Pieces and the Effect of Daily Cleaning
Authors: Fujita H. , Hansen B. , Hanel R. 
Published: February 2013

BackgroundStethoscopes are a potential source of nosocomial infection for hospitalized humans, a phenomenon not previously studied in companion animals.ObjectivesTo determine if daily cleaning of stethoscope chest pieces reduces bacterial contamination between cleanings.AnimalsClient‐owned dogs and cats.MethodsProspective observational study. In phase 1, bacterial cultures were obtained from the chest pieces of 10 participant stethoscopes once weekly for 3 weeks. In phase 2, stethoscopes were cleaned daily and 2 culture samples were obtained once weekly, immediately before and after cleaning with 70% isopropyl alcohol, for 3 weeks.ResultsDaily cleaning eliminated bacteria immediately after each cleaning (P = .004), but did not reduce the rate of positive cultures obtained before cleaning in phase 2. Cultures were positive for 20/30 (67%) samples during phase 1 and 18/30 (60%) obtained before daily cleaning during phase 2. Recovered organisms included normal skin flora, agents of opportunistic infections, and potential pathogens. The only genus that was repeatedly recovered from the same stethoscope for 2 or more consecutive weeks was Bacillus sp.Conclusions and Clinical ImportanceDaily cleaning was highly effective at removing bacteria, but provided no reduction in precleaning contamination. Cleaning stethoscopes after use on dogs or cats infected with pathogenic bacteria and before use on immunocompromised animals should be considered.
Dealing with change: the different microenvironments faced by the malarial parasite
Authors: Chitnis Chetan E. , Staines Henry M. 
Published: February 2013

SummaryIn a new paper, Pillai et al. () report that in vitro asexual blood‐stage Plasmodium falciparum parasite cultures are able to grow unhindered in media with surprisingly broad ranges of ionic constituents. In doing so, the authors demonstrate that long known changes in the cationic composition of the cytosol of host erythrocytes induced by developing intra‐erythrocytic parasites are not essential for growth. Moreover, their results also suggest that besides a low K+ environment, which has been shown to trigger key processes such as microneme secretion and merozoite egress, there must be alternative signals that can regulate these processes and allow normal growth in diverse ionic environments. Given these findings, mechanisms by which the parasite is able to sense and tolerate different ionic environments are worthy of further study in an effort to identify urgently needed novel anti‐malarial strategies.
Functional insights into the Shigella type III needle tip IpaD in secretion control and cell contact
Authors: Schiavolin Lionel , Meghraoui Alaeddine , Cherradi Youness , Biskri Latéfa , Botteaux Anne , Allaoui Abdelmounaaïm 
Published: February 2013

SummaryType III secretion apparatus (T3SA) are complex nanomachines that insert a translocation pore into the host cell membrane through which effector proteins are injected into the cytosol. In Shigella, the pore is inserted by a needle tip complex that also controls secretion. IpaD is the key protein that rules the composition of the tip complex before and upon cell contact or Congo red (CR) induction. However, how IpaD is involved in secretion control and translocon insertion remains not fully understood. Here, we report the phenotypic analysis of 20 10‐amino acids deletion variants all along the coiled‐coil and the central domains of IpaD (residues 131–332). Our results highlight three classes of T3S phenotype; (i) wild‐type secretion, (ii) constitutive secretion of all classes of effectors, and (iii) constitutive secretion of translocators and early effectors, but not of late effectors. Our data also suggest that the composition of the tip complex defines both the T3SA inducibility state and late effectors secretion. Finally, we shed light on a new aspect regarding the contact of the needle tip with cell membrane by uncoupling the Shigella abilities to escape macrophage vacuole, and to insert the translocation pore or to invade non‐phagocytic cells.
Ubiquilin‐1 immunoreactivity is concentrated on Hirano bodies and dystrophic neurites in Alzheimer's disease brains
Authors: Satoh J. , Tabunoki H. , Ishida T. , Saito Y. , Arima K. 
Published: February 2013

AimsUbiquilin‐1 acts as an adaptor protein that mediates the translocation of polyubiquitinated proteins to the proteasome for degradation. Although previous studies suggested a key role of ubiquilin‐1 in the pathogenesis of Alzheimer's disease (AD), a direct relationship between ubiquilin‐1 and Hirano bodies in AD brains remains unknown.MethodsBy immunohistochemistry, we studied ubiquilin‐1 and ubiquilin‐2 expression in the frontal cortex and the hippocampus of six AD and 13 control cases.ResultsNumerous Hirano bodies, accumulated in the hippocampal CA1 region of AD brains, expressed intense immunoreactivity for ubiquilin‐1. They were much less frequently found in control brains. However, Hirano bodies did not express a panel of markers for proteasome, autophagosome or pathogenic proteins, such as ubiquilin‐2, ubiquitin, p62, LC3, beclin‐1, HDAC6, paired helical filament (PHF)‐tau, protein‐disulphide isomerase (PDI) and phosphorylated TDP‐43, but some of them expressed C9orf72. Ubiquilin‐1‐immunoreactive deposits were classified into four distinct morphologies, such as rod‐shaped structures characteristic of Hirano bodies, dystrophic neurites contacting senile plaques, fragmented structures accumulated in the lesions affected with severe neuronal loss, and thread‐shaped structures located mainly in the molecular layer of the hippocampus.ConclusionsUbiquilin‐1 immunoreactivity is concentrated on Hirano bodies and dystrophic neurites in AD brains, suggesting that aberrant expression of ubiquilin‐1 serves as one of pathological hallmarks of AD.
Contrasting arbuscular mycorrhizal communities colonizing different host plants show a similar response to a soil phosphorus concentration gradient
Authors: Gosling Paul , Mead Andrew , Proctor Maude , Hammond John P. , Bending Gary D. 
Published: February 2013

Summary

High soil phosphorus (P) concentration is frequently shown to reduce root colonization by arbuscular mycorrhizal (AM) fungi, but the influence of P on the diversity of colonizing AM fungi is uncertain.

We used terminal restriction fragment length polymorphism (T‐RFLP) of 18S rDNA and cloning to assess diversity of AM fungi colonizing maize (Zea mays), soybean (Glycene max) and field violet (Viola arvensis) at three time points in one season along a P gradient of 10–280 mg l−1 in the field.

Percentage AM colonization changed between sampling time points but was not reduced by high soil P except in maize. There was no significant difference in AM diversity between sampling time points. Diversity was reduced at concentrations of P > 25 mg l−1, particularly in maize and soybean. Both cloning and T‐RFLP indicated differences between AM communities in the different host species. Host species was more important than soil P in determining the AM community, except at the highest P concentration.

Our results show that the impact of soil P on the diversity of AM fungi colonizing plants was broadly similar, despite the fact that different plants contained different communities. However, subtle differences in the response of the AM community in each host were evident.
Is self‐fertilization an evolutionary dead end?
Authors: Igic Boris , Busch Jeremiah W. 
Published: February 2013

SummaryA compound hypothesis positing that self‐fertilization is an evolutionary dead end conflates two distinct claims: the transition from outcrossing to selfing is unidirectional; and the diversification rate, or the balance of the speciation and extinction rate, is negative for selfing species. Both claims have enjoyed widespread informal support for decades, but have recently come under suspicion. Sources of data that apparently contradict strongly asymmetric mating system transitions often rely on statistical phylogenetic tests plagued by profound flaws. Although recently developed models mend preceding approaches, they have been employed sparingly, and many problems remain. Theoretical investigations, genetic data and applications of new phylogenetic methods provide indirect support for an association of selfing with negative diversification rates. We lack direct tests of reversals from selfing to outcrossing, and require data concerning the genetic basis and complexity of independently evolved outcrossing adaptations. The identification of the mechanisms that limit the longevity of selfing lineages has been difficult. Limitations may include brief and variable durations of selfing lineages, as well as ongoing difficulties in relating additive genetic and nucleotide variation. Furthermore, a common line of evidence for the stability of mixed mating – based simply on its frequent occurrence – is misleading. We make specific suggestions for research programs that aim to provide a richer understanding of mating system evolution and seriously challengeStebbins’ venerable hypothesis.ContentsSummary386I.Introduction387II.Microevolutionary perspectives on SEDE388III.Macroevolutionary perspectives on SEDE390IV.SEDE and the distribution of outcrossing rates in angiosperms393V.Redirection of study to challenge Stebbins’ claims394Acknowledgements395References395
Ancestral stomatal control results in a canalization of fern and lycophyte adaptation to drought
Authors: McAdam Scott A. M. , Brodribb Timothy J. 
Published: February 2013

Summary

Little is known about how a predominantly passive hydraulic stomatal control in ferns and lycophytes might impact water use under stress. Ferns and lycophytes occupy a diverse array of habitats, from deserts to rainforest canopies, raising the question of whether stomatal behaviour is the same under all ecological strategies and imposes ecological or functional constraints on ferns and lycophytes.

We examined the stomatal response of a diverse sample of fern and lycophyte species to both soil and atmospheric water stress, assessing the foliar level of the hormone abscisic acid (ABA) over drought and recovery and the critical leaf water potential (Ψl) at which photosynthesis in droughted leaves failed to recover.

The stomata of all ferns and lycophytes showed very predictable responses to soil and atmospheric water deficit via Ψl, while stomatal closure was poorly correlated with changes in ABA. We found that all ferns closed stomata at very low levels of water stress and their survival afterwards was limited only by their capacitance and desiccation tolerance.

Ferns and lycophytes have constrained stomatal responses to soil and atmospheric water deficit as a consequence of a predominantly passive stomatal regulation. This results in a monotypic strategy in ferns and lycophytes under water stress.
Alterations in inflammatory, antiviral and regulatory cytokine responses in peripheral blood mononuclear cells from pregnant women with asthma
Authors: Vanders Rebecca L. , Gibson Peter G. , Wark Peter A. B. , Murphy Vanessa E. 
Published: February 2013

AbstractBackground & objectiveSevere asthma exacerbations during pregnancy are a common complication leading to poor health outcomes for both the mother and the baby. Asthma exacerbations are caused most frequently by respiratory viruses. A balance between antiviral and inflammatory immune responses is critical during pregnancy; the balance may be altered by asthma and respiratory virus infection.MethodsPeripheral blood mononuclear cells (PBMCs) were isolated from (i) non‐pregnant healthy controls, (ii) pregnant non‐asthmatics, (iii) post‐partum non‐asthmatics, (iv) non‐pregnant asthmatics (v) pregnant asthmatics, and (vi) post‐partum asthmatics. Cells were culturedin vitrowith the mitogen phytohaemagglutinin or with a strain of the 2009 pandemic swine influenza. Interferon(IFN)‐γ, interleukin (IL)‐10 andIL‐17 protein were measured from culture supernatant. Neutrophil counts were obtained in samples from pregnant and post‐partum women.ResultsFollowing the phytohaemagglutinin stimulation ofPBMCs, pregnant asthmatics had significantly higherIL‐17 and significantly lowerIFN‐γ responses compared with healthy non‐pregnant women. Following infection with influenza, a significant reduction was also observed inIFN‐γandIL‐10production fromPBMCof pregnant asthmatics. TheIL‐17response to phytohaemagglutinin correlated with the neutrophil percentage. Differences inIFN‐γ,IL‐10andIL‐17were found to persist for at least 6 months post‐partum.ConclusionsA reduction in antiviral and regulatory immunity with increased inflammation during pregnancy occurs inPBMCfrom pregnant women with asthma. This novel information may relate to the increased susceptibility and disease severity to respiratory virus infections observed during pregnancy.
Social judgment of aggressive language: Effects of target and sender sex on the evaluation of slurs
Authors: Bendixen Mons , Gabriel Ute 
Published: February 2013

We investigated the influence of the sex of the target and the sex of the sender on the judgment of slurs (verbal derogation). From previous research, we selected and clustered slurs into seven categories and respondents rated their degree of perceived insult in two consecutive questionnaire surveys (N = 281 and N = 224, respectively). Results confirm that slurs are generally judged as being more insulting when directed towards females than towards males. In comparison, differences in sex of sender were small. When directed towards females, slurs referring to “being loose” were rated as the most insulting. For both target sexes, remarks referring to homosexuality and physical unattractiveness were among those rated as the most insulting. Least insulting were slurs referring to unethical acts, lack of intelligence and cowardliness. A sex of respondent effect was found, suggesting that women rated slurs generally more insulting than men. The pattern of results showed considerable stability across surveys attesting for the reliability of the method for measuring the social evaluation of slurs.
Light and the E3 ubiquitin ligase COP1/SPA control the protein stability of the MYB transcription factors PAP1 and PAP2 involved in anthocyanin accumulation in Arabidopsis
Authors: Maier Alexander , Schrader Andrea , Kokkelink Leonie , Falke Christian , Welter Bastian , Iniesto Elisa , Rubio Vicente , Uhrig Joachim F. , Hülskamp Martin , Hoecker Ute 
Published: February 2013

SummaryAnthocyanins are natural pigments that accumulate only in light‐grown and not in dark‐grown Arabidopsis plants. Repression of anthocyanin accumulation in darkness requires the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA‐105 (COP1/SPA) ubiquitin ligase, as cop1 and spa mutants produce anthocyanins also in the dark. Here, we show that COP1 and SPA proteins interact with the myeloblastosis (MYB) transcription factors PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP)1 and PAP2, two members of a small protein family that is required for anthocyanin accumulation and for the expression of structural genes in the anthocyanin biosynthesis pathway. The increased anthocyanin levels in cop1 mutants requires the PAP1 gene family, indicating that COP1 functions upstream of the PAP1 gene family. PAP1 and PAP2 proteins are degraded in the dark and this degradation is dependent on the proteasome and on COP1. Hence, the light requirement for anthocyanin biosynthesis results, at least in part, from the light‐mediated stabilization of PAP1 and PAP2. Consistent with this conclusion, moderate overexpression of PAP1 leads to an increase in anthocyanin levels only in the light and not in darkness. Here we show that SPA genes are also required for reducing PAP1 and PAP2 transcript levels in dark‐grown seedlings. Taken together, these results indicate that the COP1/SPA complex affects PAP1 and PAP2 both transcriptionally and post‐translationally. Thus, our findings have identified mechanisms via which the COP1/SPA complex controls anthocyanin levels in Arabidopsis that may be useful for applications in biotechnology directed towards increasing anthocyanin content in plants.
Phase II Clinical Study of BC-3781, a Pleuromutilin Antibiotic, in Treatment of Patients with Acute Bacterial Skin and Skin Structure Infections
Authors: Prince W. T. , Ivezic-Schoenfeld Z. , Lell C. , Tack K. J. , Novak R. , Obermayr F. , Talbot G. H. 
Published: February 2013

ABSTRACT

This study investigated the potential of the novel systemic pleuromutilin antibiotic BC-3781 to treat patients with an acute bacterial skin and skin structure infection (ABSSSI) caused by a Gram-positive pathogen. Patients were randomized to intravenous BC-3781 100 mg, BC-3781 150 mg, or vancomycin 1 g every 12 h. Response to treatment was assessed daily and at test of cure (TOC). The primary endpoint was the clinical success rate at TOC in the modified intent-to-treat (MITT) and clinically evaluable (CE) analysis populations. Baseline characteristics, including the frequency of methicillin-resistant
Staphylococcus aureus
(MRSA), were comparable between the different treatment groups. Of 210 patients randomized, 186 (88.6%) patients completed the study. Clinical success at TOC in the CE population occurred in 54 (90.0%) patients in the BC-3781 100-mg group, 48 (88.9%) in the BC-3781 150-mg group, and 47 (92.2%) in the vancomycin group. At day 3, the clinical response rate was similar across the three treatment groups. Six patients discontinued study medication following an adverse event. The incidence rate for drug-related adverse events was lower for patients receiving BC-3781 (34.3% and 39.4% in the 100-mg and 150-mg groups, respectively) than those receiving vancomycin (53.0%). When BC-3781 was used to treat ABSSSIs caused by a Gram-positive pathogen, including MRSA, clinical success rates were comparable to those of the comparator, vancomycin. BC-3781 was generally well tolerated. These results provide the first proof of concept for the systemic use of a pleuromutilin antibiotic for the treatment of ABSSSIs.
Activities of Vancomycin-Containing Regimens against Colistin-Resistant Acinetobacter baumannii Clinical Strains
Authors: O'Hara Jessica A. , Ambe Lauretta A. , Casella Leila G. , Townsend Bethany M. , Pelletier Mark R. , Ernst Robert K. , Shanks Robert M. Q. , Doi Yohei 
Published: February 2013

ABSTRACT

Treatment of infections due to extensively drug-resistant (XDR)
Acinetobacter baumannii
often involves the use of antimicrobial agents in combination. Various combinations of agents have been proposed, with colistin serving as the backbone in many of them. Recent data suggest that glycopeptides, in particular vancomycin, may have unique activity against laboratory-adapted and clinical strains of
A. baumannii
, alone and in combination with colistin. The aim of the present study was to test this approach against three unique colistin-resistant
A. baumannii
clinical strains using combinations of vancomycin (VAN), colistin (COL), and doripenem (DOR). All three strains possessed the signature phosphoethanolamine modification of the lipid A moiety associated with colistin resistance and unique amino acid changes in the PmrAB two-component signal transduction system not observed in colistin-susceptible strains. In checkerboard assays, synergy (defined as a fractional inhibitory concentration index [FICI] of ≤0.5) was observed between COL and VAN for all three strains tested and between COL and DOR in two strains. In time-kill assays, the combinations of COL-DOR, COL-VAN, and COL-DOR-VAN resulted in complete killing of colistin-resistant
A. baumannii
in 1, 2, and all 3 strains, respectively. In the
Galleria mellonella
moth model of infection, the combinations of DOR-VAN and COL-DOR-VAN led to significantly increased survival of the larvae, compared with other combinations and monotherapy. These findings suggest that regimens containing vancomycin may confer therapeutic benefit for infection due to colistin-resistant
A. baumannii
.
Quantification of the Adenylate Cyclase Toxin of Bordetella pertussisIn Vitroand during Respiratory Infection
Authors: Eby Joshua C. , Gray Mary C. , Warfel Jason M. , Paddock Christopher D. , Jones Tara F. , Day Shandra R. , Bowden James , Poulter Melinda D. , Donato Gina M. , Merkel Tod J. , Hewlett Erik L. 
Published: February 2013

ABSTRACTWhooping cough results from infection of the respiratory tract withBordetella pertussis, and the secreted adenylate cyclase toxin (ACT) is essential for the bacterium to establish infection. Despite extensive study of the mechanism of ACT cytotoxicity and its effects over a range of concentrationsin vitro, ACT has not been observed or quantifiedin vivo, and thus the concentration of ACT at the site of infection is unknown. The recently developed baboon model of infection mimics the prolonged cough and transmissibility of pertussis, and we hypothesized that measurement of ACT in nasopharyngeal washes (NPW) from baboons, combined with human andin vitrodata, would provide an estimate of the ACT concentration in the airway during infection. NPW contained up to ∼108CFU/mlB. pertussisand 1 to 5 ng/ml ACT at the peak of infection. Nasal aspirate specimens from two human infants with pertussis contained bacterial concentrations similar to those in the baboons, with 12 to 20 ng/ml ACT. When ∼108CFU/ml of a laboratory strain ofB. pertussiswas culturedin vitro, ACT production was detected in 60 min and reached a plateau of ∼60 ng/ml in 6 h. Furthermore, when bacteria were brought into close proximity to target cells by centrifugation, intoxication was increased 4-fold. Collectively, these data suggest that at the bacterium-target cell interface during infection of the respiratory tract, the concentration of ACT can exceed 100 ng/ml, providing a reference point for future studies of ACT and pertussis pathogenesis.
The Cpx Stress Response System Potentiates the Fitness and Virulence of Uropathogenic Escherichia coli
Authors: Debnath Irina , Norton J. Paul , Barber Amelia E. , Ott Elizabeth M. , Dhakal Bijaya K. , Kulesus Richard R. , Mulvey Matthew A. 
Published: February 2013

ABSTRACT

Strains of uropathogenic
Escherichia coli
(UPEC) are the primary cause of urinary tract infections, representing one of the most widespread and successful groups of pathogens on the planet. To colonize and persist within the urinary tract, UPEC must be able to sense and respond appropriately to environmental stresses, many of which can compromise the bacterial envelope. The Cpx two-component envelope stress response system is comprised of the inner membrane histidine kinase CpxA, the cytosolic response regulator CpxR, and the periplasmic auxiliary factor CpxP. Here, by using deletion mutants along with mouse and zebrafish infection models, we show that the Cpx system is critical to the fitness and virulence of two reference UPEC strains, the cystitis isolate UTI89 and the urosepsis isolate CFT073. Specifically, deletion of the
cpxRA
operon impaired the ability of UTI89 to colonize the murine bladder and greatly reduced the virulence of CFT073 during both systemic and localized infections within zebrafish embryos. These defects coincided with diminished host cell invasion by UTI89 and increased sensitivity of both strains to complement-mediated killing and the aminoglycoside antibiotic amikacin. Results obtained with the
cpxP
deletion mutants were more complicated, indicating variable strain-dependent and niche-specific requirements for this well-conserved auxiliary factor.