bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiology of ambulance responses to older people who have fallen in New South Wales, Australia
Authors: Simpson Paul M , Bendall Jason C , Patterson Jillian , Tiedemann Anne , Middleton Paul M , Close Jacqueline CT
Published: September 2012

Aim

To quantify the size and scope of the operational burden for a large ambulance service arising from older people who have fallen and to describe this population.

Methods

Retrospective analysis of ambulance records from New South Wales, Australia for emergency calls classified as ‘falls’ in the period 1 July 2008 to 30 June 2009.

Results

There were 42 331 responses to people aged 65 years or older, constituting 5.1% of total emergency workload. The median age of patients was 83 (interquartile range 76–87) and 62% were women. The transport rate was 76%. Transport to hospital was more likely during the day (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.7–1.9) and on weekends (OR 1.06, 95%CI 1.0–1.1).

Conclusion

Falls by older people constitute approximately 5% of all emergency responses, of which one quarter are not transported to emergency department (ED) after paramedic assessment. Increasing the sophistication of ambulance dispatch processes to older people who have fallen, and continuing with the development of new models of care aimed at decreasing unnecessary transports to the EDs, should be a priority when planning ambulance service delivery for older people who have fallen.
Australian emergency clinicians' perceptions and use of the GIVE Clinical Trigger for identification of potential organ and tissue donors
Authors: Neate Sandra , Marck Claudia H , Weiland Tracey J , Cunningham Nicola , Hickey Bernadette B , Dwyer Bernadine M , Jelinek George A
Published: September 2012

Objectives

In 2010 the Australian Organ and Tissue Authority introduced a nationally consistent indicator, the GIVE Clinical Trigger, for early identification of potential organ and tissue donors in EDs and intensive care units. This national survey of emergency clinicians aimed to assess emergency clinicians' perceptions and use of the Trigger.

Methods

National cross‐sectional survey of Australasian College for Emergency Medicine (ACEM) fellows and trainees and members of the College of Emergency Nursing Australia (CENA); online questionnaire; 12 items addressing implementation of the GIVE Trigger; graded and free‐text responses.

Results

Five hundred and ninety‐nine (20.2%) of 2969 ACEM members and 212 (20.7%) of 1026 CENA members responded. Four hundred and seventy‐four respondents (62.7%) were familiar with the Trigger; 472 (63.8%) agreed it was easy to recognise patients who activated the Trigger; 490 (64.9%) had sufficient time to use the Trigger; 511 (67.7%) felt they had the necessary competence and knowledge to identify a potential donor; 464 (61.5%) felt competent and 501 (66.4%) felt comfortable referring a potential donor when identified. Overall 587 (77.7%) ED clinicians supported the use of the Trigger, but most (587 [77.7%]) perceived barriers to its use; 628 (80%) had never activated the Trigger and 557 (71%) had never referred a potential donor to relevant authorities.

Conclusion

Most Australian emergency clinicians are familiar with and support the GIVE Clinical Trigger, and feel they have the necessary skills to use the Trigger; however, most perceive barriers to its use and have not yet used the Trigger.
60 Years of Development of the Journal of Integrative Plant Biology
Authors: Cui Jinzhong , He Ping , Liu Fenghong , Tan Jingjing , Chen Lingfeng , Fenn Joshua
Published: September 2012

In celebration of JIPB's 60th anniversary, this paper summarizes and reviews the development process of the journal. To start, we offer our heartfelt thanks to JIPB's pioneer Editors‐in‐Chief who helped get the journal off the ground and make it successful. Academic achievement is the soul of academic journals, and this paper summarizes JIPB's course of academic development by analyzing it in four stages: the first two stages are mostly qualitative analyses, and the latter two stages are dedicated to quantitative analyses. Most‐cited papers were statistically analyzed. Improvements in editing, publication, distribution and online accessibility—which are detailed in this paper—contribute to JIPB's sustainable development. In addition, JIPB's evaluation index and awards are provided with accompanying pictures. At the end of the paper, JIPB's milestones are listed chronologically. We believe that JIPB's development, from a national journal to an international one, parallels the development of the Chinese  plant sciences.
LHD1, an Allele of DTH8/Ghd8, Controls Late Heading Date in Common Wild Rice (Oryza rufipogon)F
Authors: Dai Xiaodong , Ding Younian , Tan Lubin , Fu Yongcai , Liu Fengxia , Zhu Zuofeng , Sun Xianyou , Sun Xuewen , Gu Ping , Cai Hongwei , Sun Chuanqing
Published: September 2012

Flowering at suitable time is very important for plants to adapt to complicated environments and produce their seeds successfully for reproduction. In rice (Oryza rufipogon Griff.) photoperiod regulation is one of the important factors for controlling heading date. Common wild rice, the ancestor of cultivated rice, exhibits a late heading date and a more sensitive photoperiodic response than cultivated rice. Here, through map‐based cloning, we identified a major quantitative trait loci (QTL) LHD1 (Late Heading Date 1), an allele of DTH8/Ghd8, which controls the late heading date of wild rice and encodes a putative HAP3/NF‐YB/CBF‐A subunit of the CCAAT‐box‐binding transcription factor. Sequence analysis revealed that several variants in the coding region of LHD1 were correlated with a late heading date, and a further complementary study successfully rescued the phenotype. These results suggest that a functional site for LHD1 could be among those variants present in the coding region. We also found that LHD1 could down‐regulate the expression of several floral transition activators such as Ehd1, Hd3a and RFT1 under long‐day conditions, but not under short‐day conditions. This indicates that LHD1 may delay flowering by repressing the expression of Ehd1, Hd3a and RFT1 under long‐day conditions.
Regulation of Brassinosteroid Biosynthesis and InactivationF
Authors: Zhao Baolin , Li Jia
Published: September 2012

Brassinosteroids (BRs) are a group of naturally‐occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analytical chemistry, genetics, and biochemistry, the major BR biosynthetic pathway has been largely elucidated. The least‐understood knowledge in the BR research field is probably the molecular mechanisms controlling the bioactive levels of BRs in response to various developmental and environmental cues. In this review, we focus our discussion on a recently‐proposed, 8‐step predominant BR biosynthetic pathway, several newly‐identified transcription factors regulating the expression of key enzymes that catalyze BR biosynthesis, and up‐to‐date information about the mechanisms that plants use to inactivate unnecessary BRs.

image

[ Jia Li (Corresponding author)]
Biochemical characterization of chitin synthase activity and inhibition in the African malaria mosquito, Anopheles gambiae
Authors: Zhang Xin , Yan Zhu Kun
Published: September 2012

Abstract  Chitin synthase (CHS) is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control. However, our understanding of biochemical properties of insect CHSs has been very limited. We here report enzymatic and inhibitory properties of CHS prepared from the African malaria mosquito, Anopheles gambiae. Our study, which represents the first time to use a nonradioactive method to assay CHS activity in an insect species, determined the optimal conditions for measuring the enzyme activity, including pH, temperature, and concentrations of the substrate uridine diphosphate N‐acetyl‐d‐glucosamine (UDP‐GlcNAc) and Mg++. The optimal pH was about 6.5–7.0, and the highest activity was detected at temperatures between 37°C and 44°C. Dithithreitol is required to prevent melanization of the enzyme extract. CHS activity was enhanced at low concentration of GlcNAc, but inhibited at high concentrations. Proteolytic activation of the activity is significant both in the 500 ×g supernatant and the 40 000 ×g pellet. Our study revealed only slight in vitro inhibition of A. gambiae CHS activity by diflubenzuron and nikkomycin Z at the highest concentration (2.5 μmol/L) examined. There was no in vitro inhibition by polyoxin D at any concentration examined. Furthermore, we did not observe any in vivo inhibition of CHS activity by any of these chemicals at any concentration examined. Our results suggest that the inhibition of chitin synthesis by these chemicals is not due to direct inhibition of CHS in A. gambiae.
Antioxidant and Free Radical Scavenging Activities of Different Plant Parts from Two Erica Species
Authors: Nunes Ricardo , Anastácio Ana , Carvalho Isabel S.
Published: September 2012

Aqueous extractions from two species of Erica consumed as infusions in several countries to heal ailments were investigated for their phenolic and flavonoid contents, along with antioxidant capacity and radical scavenging capacity using total antioxidant activity, ferric‐reducing antioxidant power, reducing power, 1,1‐diphenyl‐2‐picrylhydrazyl and 2‐2'‐azino‐bis(3 ethylbenzothiazoline‐6‐sulfonic acid) radicals, respectively. Antioxidant properties and total phenolic content differed significantly among these plants. Aqueous extracts of leaves possessed, on average, the highest antioxidant capacity and phenolic content (34.09 ± 10.81 mg ascorbic acid equivalent/g dry weight and 30.59 ± 10.19 mg gallic acid equivalent/g dry weight, respectively) of all three plant parts. A significant correlation (r2 = 0.952) between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants. Upon application of hierarchical cluster analysis to the results obtained, leaves with flowers were grouped in one cluster, whereas branches remained in another cluster, showing little interference from the collection site or species factors.

Practical Applications

Results obtained support that there may exist benefits for health from ingesting this plant infusions and that these plants have a great potential to serve as a cheap antioxidant source.
Intraclass Correlation Coefficient (ICC): A Framework for Monitoring and Assessing Performance of Trained Sensory Panels and Panelists
Authors: Bi Jian , Kuesten Carla
Published: September 2012

Sensory measurement underlies sensory science. Sensory analysis and decision‐making heavily depend on the quality of sensory data, which is determined by the performance of trained sensory panels and panelists. Various methods have been proposed for monitoring and assessing the performance. A weakness of the currently used methods is lack of a unified framework for various criteria and a variety of experiments with different types of data. This paper proposes to use accuracy, validity and reliability as general terminologies to describe sensory measurement and to apply the intraclass correlation coefficient (ICC) as a framework for monitoring and assessing performance.ICCcan measure both similarity among panelists and sensitivity of panels and panelists. Hence, ICC can handle the problems of both reliability and validity.ICCcan be obtained from different types of data for diverse experiments. This paper provides the equations andRandS‐Plus functions for estimations ofICCs from continuous data (ratings), multivariate continuous data, ordinal data, ranking data, binary‐choice data, multiple‐choice data and forced‐choice data. Confidence intervals, variances of the estimators, comparison with a fixed value and difference and similarity tests for multipleICCs are also provided. The relationship betweenCronbach's coefficient alpha andICCis discussed.

Practical Applications

Intraclass correlation coefficient (ICC) may play a framework role in monitoring and assessing performance of trained sensory panels and panelists. It can be used as an index of the quality of sensory data. The larger theICCorCronbach's coefficient alpha value, the better the performance of panels and panelists. If and only if anICCis significantly larger than a specified value, can the quality of the data for that attribute be regarded as acceptable. A statistical test that fails to show that anICCorCronbach's coefficient alpha is significantly larger than a specified lowest limit, e.g., 0.1, suggests that the products are undiscriminating, or the sensory data, at least for that attribute, might not be valid and reliable. We should use that data with caution.
Immune‐mediated myasthenia gravis in a methimazole‐treated cat
Authors: Bell E. T. , Mansfield C. S. , James F. E.
Published: September 2012

A 12‐year‐old female neutered ragdoll crossbred cat was presented for investigation of generalised weakness and regurgitation. The cat was being treated with transdermal methimazole for hyper‐thyroidism, which had been diagnosed 10 weeks previously. An acetylcholine receptor antibody titre was consistent with acquired myasthenia gravis. Withdrawal of methimazole and treatment with pyridostigmine was followed by resolution of clinical signs and reduction of the acetylcholine ‐receptor antibody titre. Medical control of hyperthyroidism was subsequently achieved with carbimazole, administered in conjunction with pyridostigmine, and no recurrence of clinical signs was observed. Myasthenia gravis is an uncommon but clinically significant adverse effect of methimazole therapy in cats, and may be caused by immunomodulatory properties of this drug. An adverse drug reaction should be considered in cats receiving methimazole that develop myasthenia gravis, and potentially also other immune‐mediated disorders.
Analysis of 14,008 uroliths from dogs in theUKover a 10‐year period
Authors: Roe K. , Pratt A. , Lulich J. , Osborne C. , Syme H. M.
Published: September 2012

Objectives

To identify breed‐associated risk factors for urolithiasis in dogs from theUK.

Methods

Records of all canine uroliths submitted to Hills Pet NutritionUKfor analysis at the University of Minnesota Urolith Centre over 10 years (1997 to 2006) were reviewed. The results, along with the request forms completed by the submitting veterinarian, were analysed. The most commonly affected breeds, age and gender of the dogs were identified for each of the most common types of uroliths (struvite, calcium oxalate, urate, cystine and mixed). Pearson's chi‐squared tests were performed to assess whether certain breeds of dogs were over‐represented relative to a reference population (from an insurance database).

Results

The records of 14,008 urolith submissions were analysed. The relative frequency of struvite remained stable over time, whereas calcium oxalate decreased over the study period. Breeds found to be significantly over‐represented for calcium oxalate uroliths included the Chihuahua, miniature poodle and Yorkshire terrier. Staffordshire bull terriers and English bulldogs were at increased risk for cystine uroliths.

Clinical Significance

Associations between breed, gender, age and urolith formation were similar to those reported elsewhere. However, temporal trends and novel breed predispositions were identified.
Catheter‐Based Renal Sympathetic Denervation Improves Central Hemodynamics and Arterial Stiffness: A Pilot Study
Authors: Mortensen Kai , Franzen Klaas , Himmel Frank , Bode Frank , Schunkert Heribert , Weil Joachim , Reppel Michael
Published: September 2012

J Clin Hypertens (Greenwich). 2012;14:861–870. ©2012 Wiley Periodicals, Inc.

Renal sympathetic denervation (RDN) is a novel treatment strategy for patients with resistant arterial hypertension. Recently, the Symplicity trials demonstrated significant peripheral blood pressure (BP) reduction. The present study aimed at measuring central aortic pressures and arterial stiffness as better predictors for cardiovascular risk in patients undergoing RDN. RDN was performed in 21 patients (systolic peripheral BP ≥150 mm Hg) with an Ardian/Medtronic (Mountain View, CA) ablation system. Data were recorded with an Arteriograph. After 6 months, peripheral systolic BP was reduced by 6.1% (P<.05) while central systolic pressure was reduced by 7.0% (P<.05). Subgroup analysis showed that in responders, peripheral systolic BP was reduced by 16.1% (P<.01) while central systolic pressure was reduced by 18.3% (P<.01). Arterial stiffness improved significantly. Aortic augmentation index (AIx) improved by 9.5% (P<.05). In responders, AIx improved by 19.2% (P<.02). Pulse wave velocity (PWV) was high at baseline (10.8 m/s) and improved by 10.4% (P<.05). In responders, PWV improved by 13.7% (P<.05). Multivariate analysis showed that short‐term effects on PWV were BP‐related, whereas during follow‐up, improvement of PWV becomes BP‐unrelated. RDN improves peripheral and central blood pressure as well as arterial stiffness and, thus, may improve cardiovascular outcome.
Interpersonal Forgiveness in Emotion‐Focused Couples' Therapy: Relating Process to Outcome
Authors: Woldarsky Meneses Catalina , Greenberg Leslie S.
Published: September 2012

The objective of this study was to relate the in‐session processes involved in interpersonal forgiveness to outcome. The sample consisted of 33 couples who received 10–12 sessions of Emotion‐focused couple therapy with the aim of resolving various forms of emotional injuries (i.e., transgression that violates the expectations of a close relationship, which leaves one partner feeling hurt and angry). The results of the present study were based on the analyses of 205 video‐taped segments from 33 couples' therapies. Hypotheses relating the role of three in‐session components of resolution, the injurer's “expression of shame”; the injured partner's “accepting response” to the shame, and the injured partner's “in‐session expression of forgiveness”, to outcome were tested using hierarchical linear regression analyses. Outcome measures included the Enright Forgiveness Inventory (The Enright Forgiveness Inventory user's manual. Madison: The International Forgiveness Institute, 2000), the Dyadic Adjustment Scale (Journal of Marriage and Family, 1976; 13: 723) and the The Interpersonal Trust Scale (Trust; Journal of Personality and Social Psychology, 1985; 49: 95).
Responsive Persistence Part II. Practices of Postmodern Therapists
Authors: Sutherland Olga , Dienhart Anna , Turner Jean
Published: September 2012

This article, a companion to Part I of this series of articles, discusses how therapists informed by social constructionist and postmodern ideas enact persistence in their work with families. Transcripts and video‐recordings of therapy interaction facilitated by selected major champions for three postmodern (collaborative) therapies: Michael White (narrative therapy), Harlene Anderson (collaborative language systems approach), and Bill O'Hanlon (solution‐oriented therapy) were examined for persistence practices. The article offers a range of possible ways in which postmodern therapists may enact their influence in facilitating generative and helpful conversations with families and remain responsive to clients' preferences and understandings. Implications for family therapy practice, training, and supervision are discussed.
Navigating Dual Relationships in Rural Communities
Authors: Gonyea Jennifer L. J. , Wright David W. , Earl‐Kulkosky Terri
Published: September 2012

The literature examining dual relationships in rural communities is limited, and existing ethical guidelines lack guidelines about how to navigate these complex relationships. This study uses grounded theory to explore rural therapists' perceptions of dual relationship issues, the perceived impact of minority and/or religious affiliation on the likelihood of dual relationships, and the ways rural therapists handle inevitable dual relationship situations. All of the therapists who participated in the study practiced in small communities and encountered dual relationship situations with regularity. The overarching theme that emerged from the data was that of using professional judgment in engaging in the relationship, despite the fact that impairment of professional judgment is the main objection to dual relationships. This overall theme contained three areas where participants felt they most needed to use their judgment: the level of benefit or detriment to the client, the context, and the nature of the dual relationship. Surprisingly, supervision and/or consultation were not mentioned by the participants as strategies for handling dual relationships. The results of this study are compared with established ethical decision‐making models, and implications for the ethical guidelines and appropriate ethical training are suggested.
Policing: Fundamental principles in a Canadian context
Authors: Robertson Neil
Published: September 2012

This article provides an introduction to the place of Canada's police in the public service. It identifies what makes Canada's police services distinct from other parts of the public service, considers the principles under which policing is expected to operate in democratic systems, and reviews current policing challenges. Public understanding of police and police work may not be accurate, since perceptions may be overly influenced by fictional depictions of law enforcement and by police themselves. Incomplete understandings can influence public policy making, including funding decisions, to the detriment of good policing. Finally, the article observes that there may be insufficient research on policing given its aggregate cost and importance to a successful civil society.
Comparison of efficacy of three commercially available dentifrices on dentinal hypersensitivity: a randomized clinical trial
Authors: Pradeep AR , Agarwal E , Naik SB , Bajaj P , Kalra N
Published: September 2012

Background:  Dentinal hypersensitivity has been defined as a short, sharp pain arising from exposed dentine as a result of various stimuli such as heat, cold, chemical, or osmotic, that cannot be ascribed to any other pathology. This study was conducted to assess the efficacy of three commercially available toothpastes in the reduction of dentinal hypersensitivity.

Methods:  A total of 149 subjects (72 males and 77 females; aged 20 to 60 years) were entered into the study and randomly divided into four groups: Group 1 – toothpaste containing 5% potassium nitrate; Group 2 – toothpaste containing 5% calcium sodium phosphosilicate with fused silica; Group 3 – toothpaste containing 3.85% amine fluoride; and Group 4 – a placebo toothpaste. After sensitivity scores for controlled air stimulus and cold water at baseline were recorded, subjects were given toothpastes and sensitivity scores were measured again at 2 weeks and 6 weeks.

Results:  All groups showed a reduction in sensitivity scores at 2 weeks and 6 weeks. The calcium sodium phosphosilicate group was found to be significantly better compared to the other groups at the end of 6 weeks.

Conclusions:  The calcium sodium phosphosilicate group showed a better reduction in the symptoms of dentinal hypersensitivity.
The cross‐pin retained implant supported restoration: a study of gasket placement and leakage
Authors: Sambrook RJ , Judge RB
Published: September 2012

Background:  Advantages of cross‐pin retained implant supported restorations (ISRs) include predictable retrieval and predictable retention. Unlike direct to fixture (DTF) or cement retained restorations, the prosthetic design of a cross‐pinned restoration retains gaps at the interfaces between the crown, abutment and cross‐pin screw. These spaces permit leakage into the suprastructure and gasket placement has been recommended to prevent this leakage.

Methods:  Five different gaskets were assessed for their ability to prevent leakage into a cross‐pinned ISR. The gaskets tested were: cement admixture on the cross‐pin screw; cement admixture on the inner surface of the coping and the cross‐pin screw; cement admixture on the inner surface of the coping only; cement admixture placed 1 mm from the margin of the coping and a filler placed in the abutment chimney.

Results:  Only gaskets which sealed both the cross‐pin screw interface and the abutment‐crown interface prevented leakage. A filler placed in the abutment chimney prevented leakage into this space but did not prevent fluid accumulating between the coping and abutment. Conservative placement of cement at the margin of the coping failed to prevent leakage.

Conclusions:  Cement gaskets may effectively prevent leakage into a cross‐pinned ISR. However, the use of a cement as a gasket has to be weighed against the issue of predictable retrieval, cement extrusion and incomplete seating.
Effect of periodontal therapy on prevention of gastric Helicobacter pylori recurrence: a systematic review and meta‐analysis
Authors: Bouziane Amal , Ahid Samir , Abouqal Redouane , Ennibi Oumkeltoum
Published: September 2012

Aim

The aim of this review is to assess the effect of dental plaque control and periodontal therapy on prevention of gastric Helicobacter pylori (H. pylori) recurrence.

Materials and Methods

We conducted searches of electronic databases, and included controlled trials comparing periodontal treatment and eradication therapy of H. pylori with eradication therapy alone for prevention of recurrence of gastric H. pylori. We used the absence of recurrence of gastric H. pylori after the first 3 months as an outcome measure to determine relative risk of persistence of gastric H. pylori. We estimated the degree of heterogeneity among trial results using Q and I2 statistics.

Results

Three trials including 298 patients were eligible according to our inclusion criteria. As significant heterogeneity was indicated by the Q statistics (p = 0.04) and I2 (69%), we used a random‐effects model to combine the data. Compared with eradication therapy alone, the adjunction of periodontal therapy significantly reduced the relative risk of persistence of gastric H. pylori by 63% (0.37 [95% CI 0.21–0.64], p = 0.0004) in patients with gastric diseases.

Conclusions

The adjunction of periodontal treatment to eradication therapy appears to reduce gastric H. pylori recurrence compared with eradication therapy alone among patients with gastric diseases associated with H. pylori. The results of this meta‐analysis should be taken with caution because of the limitations in the primary data.
New insights into pharyngo‐esophageal bolus transport revealed by pressure‐impedance measurement
Authors: Omari T. , Kritas S. , Cock C.
Published: September 2012

Background  Pharyngeal propulsion, strength of peristalsis and esophago–gastric junction (EJG) resistance are determinants of esophageal bolus transport. This study used pressure‐impedance methods to correlate pharyngo‐esophageal function with the esophageal bolus trajectory pathway and pressures generated during bolus transport.

Methods  Pharyngo‐esophageal pressure‐impedance measurements were performed in 20 healthy adult controls. Pharyngeal automated impedance manometry (AIM) analysis was performed to derive pharyngeal swallow function variables. The esophageal time of nadir impedance (TZn) was used to track bolus trajectory pathway. The inflection, or flow stasis point (FSP), of the trajectory curve was determined as were the pressures within the bolus (PZn) above and below the FSP. The size of 20 mmHg isocontour defect (20 mmHg IC defect) measured the integrity of the peristaltic wave.

Key Results  For viscous boluses, weaker pharyngeal bolus propulsion correlated with the FSP being located higher in the esophagus. Pressure within the bolus was observed to increase at the FSP and below the FSP in a manner that correlated with the magnitude of esophageal peak pressures. Larger 20 mmHg IC defects were associated with lower pressures within the bolus at the FSP and below.

Conclusions & Inferences  The FSP of the bolus trajectory pathway appears to represent a switch from bolus propulsion due to pharyngeal mechanisms to bolus propulsion due to esophageal mechanisms. 20 mmHg IC defects significantly reduce bolus driving pressure at or below the FSP.
Integrative analysis of chromatin states in Arabidopsis identified potential regulatory mechanisms for natural antisense transcript production
Authors: Luo Chongyuan , Sidote David J. , Zhang Yi , Kerstetter Randall A. , Michael Todd P. , Lam Eric
Published: September 2012

Genome‐wide analyses of epigenomic and transcriptomic profiles provide extensive resources for discovering epigenetic regulatory mechanisms. However, the construction of functionally relevant hypotheses from correlative patterns and the rigorous testing of these hypotheses may be challenging. We combined bioinformatics‐driven hypothesis building with mutant analyses to identify potential epigenetic mechanisms using the model plant Arabidopsis thaliana. Genome‐wide maps of nine histone modifications produced by ChIP‐seq were used together with a strand‐specific RNA‐seq dataset to profile the epigenome and transcriptome of Arabidopsis. Combinatorial chromatin patterns were described by 42 major chromatin states with selected states validated using the re‐ChIP assay. The functional relevance of chromatin modifications was analyzed using the ANchored CORrelative Pattern (ANCORP) method and a newly developed state‐specific effects analysis (SSEA) method, which interrogates individual chromatin marks in the context of combinatorial chromatin states. Based on results from these approaches, we propose the hypothesis that cytosine methylation (5mC) and histone methylation H3K36me may synergistically repress production of natural antisense transcripts (NATs) in the context of actively expressed genes. Mutant analyses supported this proposed model at a significant proportion of the tested loci. We further identified polymerase‐associated factor as a potential repressor for NAT abundance. Although the majority of tested NATs were found to localize to the nucleus, we also found evidence for cytoplasmically partitioned NATs. The significance of the subcellular localization of NATs and their biological functions remain to be defined.
Survival of Escherichia coli, Enterococci and Campylobacter jejuni in Canada Goose Faeces on Pasture
Authors: Moriarty E. M. , Weaver L. , Sinton L. W. , Gilpin B.
Published: September 2012

Freshly excreted Canada goose faeces pose a public health risk as they contain pathogenic microorganisms. Accordingly, a study was carried out on the growth and survival of resident indicator bacteria (enterococci and Escherichia coli) and inoculated Campylobacter jejuni in freshly excreted faeces over summer and winter. Canada goose faeces were collected, mixed thoroughly and inoculated with 108 g−1C. jejuni. The faeces were mixed again before making the Canada goose dropping. The simulated goose droppings (N = 70) were placed on pasture, and the concentrations of E. coli, enterococci and the pathogen, C. jejuni, were monitored. In summer only, the molecular marker of E. coli LacZ and the avian‐associated bacteria E2 was also monitored. Results of the survival study indicated that significant growth of enterococci and E. coli occurred in summer, before concentrations decreased to less than 15% of the original concentration (day 77) for enterococci and 0.01% for E. coli. LacZ followed a similar pattern to E. coli, while the E2 marker dropped to below 0.1% of the original concentration within 4 days. In winter, enterococci grew slightly, while no growth of E. coli occurred. In both summer and winter, C. jejuni was rapidly inactivated. This research highlights the ability of bacterial indicators to replicate and survive in the environment when harboured by avian faeces, and the limited risk aged Canada goose faeces pose as an environmental source of Campylobacter spp.
Atomic force microscopy to characterize binding properties of α7‐containing nicotinic acetylcholine receptors on neurokinin‐1 receptor‐expressing medullary respiratory neurons
Authors: Clark Catharine G. , Sun Zhe , Meininger Gerald A. , Potts Jeffrey T.
Published: September 2012

New findings

What is the central question of this study?

Nicotinic acetylcholine receptors (nAChRs) play an important role in modulating breathing, and alterations in the functional properties of nAChRs may contribute to respiratory abnormalities, such as prenatal exposure to nicotine. Whie common approaches to study nAChRs, such as electrophysiological, anatomical and pharmacological techniques, are beneficial, they do not allow functional examination of receptor behaviour at the receptor level. We sought to use atomic force microscopy (AFM) to assess ligand‐binding properties of nAChR in living medullary neurons under control conditions and following nicotine exposure.

What is the main finding and its importance?

Our results demonstrate, for the first time, the utility of atomic force microscopy to assess functional properties of nAChRs in living medullary neurons, including the binding probability of the receptor. These findings also support the claim that nicotine desensitizes nAChRs.

In the present study, we used atomic force microscopy (AFM) to examine the ligand‐binding properties of α7‐containing nicotinic acetylcholine receptors (nAChRs) expressed on neurons from the ventral respiratory group. We also determined the effect of acute and prolonged exposure to nicotine on the binding probability of nAChRs. Neurons from neonatal (postnatal day 5–10) and juvenile rats (3–4 weeks old) were cultured. Internalization of Alexa Fluor 488‐conjugated substance P was used to identify respiratory neurons that expressed the neurokinin‐1 receptor (NK1‐R), a recognized marker of ventral respiratory group neurons. To assess functional changes in nAChRs, AFM probes conjugated with anti‐α7 subunit nAChR antibody were used to interact cyclically with the surface of the soma of NK1‐R‐positive neurons. Measurements were made of the frequency of antibody adhesion to the α7 receptor subunit and of the detachment forces between the membrane‐attached receptor and the AFM probe tip. Addition of α‐bungarotoxin (a specific antagonist of α7 subunit‐containing nAChRs) to the cell bath produced a 69% reduction in binding to the α7 subunit (P < 0.05, n= 10), supporting specificity of binding. Acute exposure to nicotine (1 μm added to culture media) produced an 80% reduction in nAChR antibody binding to the α7 subunit (P < 0.05, n= 9). Prolonged incubation (72 h) of the cell culture in nicotine significantly reduced α7 binding in a concentration‐dependent manner. Collectively, these findings demonstrate that AFM is a sensitive tool for assessment of functional changes in nAChRs expressed on the surface of living NK1‐R‐expressing medullary neurons. Moreover, these data demonstrate that nicotine exposure decreases the binding probability of α7 subunit‐containing nAChRs.
Intense intermittent exercise provides weak stimulus for vascular endothelial growth factor secretion and capillary growth in skeletal muscle
Authors: Hoier B. , Passos M. , Bangsbo J. , Hellsten Y.
Published: September 2012

New findings

What is the central question of this study?

Does intense intermittent exercise provide a sufficient angiogenic stimulus to induce capillary growth in skeletal muscle conditioned by moderate intensity exercise training?

What is the main finding and its importance?

We show that higher levels of shear stress and metabolism associated with intense exercise do not provide further stimulus for capillary growth. Instead, secretion of vascular endothelial growth factor and proliferation of endothelial cells are lower in response to intense compared with moderate‐intensity exercise, suggesting that intense exercise is a weaker stimulus for angiogenesis. The data provide novel insight into the regulation of vascular endothelial growth factor secretion in muscle and the role of pro‐angiogenic and angiostatic factors.

The effect of acute intense intermittent exercise compared with moderate‐intensity exercise on angiogenic factors and the effect of 4 weeks of intense intermittent training on capillary growth were examined in nine healthy young men, preconditioned by moderate‐intensity endurance training. The intense training consisted of 24 bouts of 1 min cycling at an initial work rate of 316 ± 19 W (∼117% of pretraining maximal oxygen uptake), performed three times per week. Skeletal muscle biopsies and muscle microdialysates were otained from the vastus lateralis before, during and after acute exercise performed at either moderate or high intensity. Comparison of the response in angiogenic factors to acute moderate‐ versus high‐intensity exercise, performed prior to the intense training intervention, revealed that intense exercise resulted in a markedly lower (∼60%; P < 0.05) increase in interstitial vascular endothelial growth factor than did moderate‐intensity exercise. Muscle interstitial fluid obtained during moderate‐intensity exercise increased endothelial cell proliferation in vitro more than interstitial fluid obtained during intense exercise (sixfold versus 2.5‐fold, respectively; P < 0.05). The 4 weeks of high‐intensity training did not lead to an increased capillarization in the muscle but abolished the exercise‐induced increase in mRNA for several angiogenic factors, increased the protein levels of endothelial nitric oxide synthase, lowered the protein levels of thrombospondin‐1 in muscle but increased the interstitial protein levels of thrombospondin‐1. We conclude that intense intermittent exercise provides a weak stimulus for vascular endothelial growth factor secretion and endothelial cell proliferation and that intense intermittent training does not induce a sufficient angiogenic stimulus to induce capillary growth in muscle previously conditioned by moderate‐intensity exercise.
Characterization of a novel phosphorylation site in the sodium–chloride cotransporter, NCC
Authors: Rosenbaek L. L. , Assentoft M. , Pedersen N. B. , MacAulay N. , Fenton R. A.
Published: September 2012

Key points

The sodium–chloride cotransporter, NCC, is essential for renal electrolyte balance and its function can be regulated by protein phosphorylation

Here we report the role and regulation of a novel phosphorylation site in NCC at Ser124

Ser124 phosphorylation plays a role in mediating full NCC transport activity, but does not seem to be involved in NCC trafficking

Various physiological stimuli such as vasopressin and aldosterone regulate the abundance of the Ser124 phosphorylation status and other phosphorylation sites in NCC

Unlike other known phosphorylation sites in NCC, the STE20/SPS1‐related proline–alanine‐rich kinase and oxidative stress‐response kinases (SPAK and OSR1) were not able to phosphorylate NCC at Ser124

The results demonstrate that phosphorylation of NCC is a major factor in determining the function of NCC under various physiological conditions

Abstract  The sodium–chloride cotransporter, NCC, is essential for renal electrolyte balance. NCC function can be modulated by protein phosphorylation. In this study, we characterized the role and physiological regulation of a novel phosphorylation site in NCC at Ser124 (S124). Novel phospho‐specific antibodies targeting pS124‐NCC demonstrated a band of 160 kDa in the kidney cortex, but not medulla, which was preabsorbed by a corresponding phosphorylated peptide. Confocal microscopy with kidney tubule segment‐specific markers localized pS124‐NCC to all distal convoluted tubule cells. Double immunogold electron microscopy demonstrated that pS124‐NCC co‐localized with total NCC in the apical plasma membrane of distal convoluted tubule cells and intracellular vesicles. Acute treatment of Munich–Wistar rats or vasopressin‐deficient Brattleboro rats with the vasopressin type 2 receptor‐specific agonist dDAVP significantly increased pS124‐NCC abundance, with no changes in total NCC plasma membrane abundance. pS124‐NCC levels also increased in abundance in rats after stimulation of the renin–angiotensin–aldosterone system by dietary low sodium intake. In contrast to other NCC phosphorylation sites, the STE20/SPS1‐related proline–alanine‐rich kinase and oxidative stress‐response kinases (SPAK and OSR1) were not able to phosphorylate NCC at S124. Protein kinase arrays identified multiple kinases that were able to bind to the region surrounding S124. Four of these kinases (IRAK2, CDK6/Cyclin D1, NLK and mTOR/FRAP) showed weak but significant phosphorylation activity at S124. In oocytes, 36Cl uptake studies combined with biochemical analysis showed decreased activity of plasma membrane‐associated NCC when replacing S124 with alanine (A) or aspartic acid (D). In novel tetracycline‐inducible MDCKII‐NCC cell lines, S124A and S124D mutants were able to traffic to the plasma membrane similarly to wildtype NCC.
Novel Method To Assess Antiretroviral Target Trough Concentrations UsingIn VitroSusceptibility Data
Authors: Acosta Edward P. , Limoli Kay L. , Trinh Lan , Parkin Neil T. , King Jennifer R. , Weidler Jodi M. , Ofotokun Ighovwerha , Petropoulos Christos J.
Published: September 2012

Durable suppression of HIV-1 replication requires the establishment of antiretroviral drug concentrations that exceed the susceptibility of the virus strain(s) infecting the patient. Minimum plasma drug concentrations (Ctrough) are correlated with response, but determination of targetCtroughvalues is hindered by a paucity ofin vivoconcentration-response data. In the absence of these data,in vitrosusceptibility measurements, adjusted for serum protein binding, can provide estimations of suppressivein vivodrug concentrations. We derived serum protein binding correction factors (PBCF) for protease inhibitors, nonnucleoside reverse transcriptase inhibitors, and an integrase inhibitor by measuring the effect of a range of human serum concentrations onin vitrodrug susceptibility measured with the PhenoSense HIV assay. PBCFs corresponding to 100% HS were extrapolated using linear regression and ranged from 1.4 for nevirapine to 77 for nelfinavir. Using the mean 95% inhibitory concentration (IC95) for ≥1,200 drug-susceptible viruses, we calculated protein-bound IC95(PBIC95) values. PBIC95values were concordant with the minimum effectiveCtroughvalues that were established in well-designed pharmacodynamic studies (e.g., indinavir, saquinavir, and amprenavir). In other cases, the PBIC95values were notably lower (e.g., darunavir, efavirenz, and nevirapine) or higher (nelfinavir and etravirine) than existing target recommendations. The establishment of PBIC95values as described here provides a convenient and standardized approach for estimation of the minimum drug exposure that is required to maintain viral suppression and prevent the emergence of drug-resistant variants, particularly whenin vivoconcentration-response relationships are lacking.
Chitin Synthases with a Myosin Motor-Like Domain Control the Resistance of Aspergillus fumigatus to Echinocandins
Authors: Jiménez-Ortigosa Cristina , Aimanianda Vishukumar , Muszkieta Laetitia , Mouyna Isabelle , Alsteens David , Pire Stéphane , Beau Remi , Krappmann Sven , Beauvais Anne , Dufrêne Yves F. , Roncero César , Latgé Jean-Paul
Published: September 2012

Aspergillus fumigatus
has two chitin synthases (
CSMA
and
CSMB
) with a myosin motor-like domain (MMD) arranged in a head-to-head configuration. To understand the function of these chitin synthases, single and double
csm
mutant strains were constructed and analyzed. Although there was a slight reduction in mycelial growth of the mutants, the total chitin synthase activity and the cell wall chitin content were similar in the mycelium of all of the mutants and the parental strain. In the conidia, chitin content in the Δ
csmA
strain cell wall was less than half the amount found in the parental strain. In contrast, the Δ
csmB
mutant strain and, unexpectedly, the Δ
csmA
/Δ
csmB
mutant strain did not show any modification of chitin content in their conidial cell walls. In contrast to the hydrophobic conidia of the parental strain, conidia of all of the
csm
mutants were hydrophilic due to the presence of an amorphous material covering the hydrophobic surface-rodlet layer. The deletion of
CSM
genes also resulted in an increased susceptibility of resting and germinating conidia to echinocandins. These results show that the deletion of the
CSMA
and
CSMB
genes induced a significant disorganization of the cell wall structure, even though they contribute only weakly to the overall cell wall chitin synthesis.
Cell Envelope Stress Response in Cell Wall-Deficient L-Forms of Bacillus subtilis
Authors: Wolf Diana , Domínguez-Cuevas Patricia , Daniel Richard A. , Mascher Thorsten
Published: September 2012

L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium
Bacillus subtilis
was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of
B. subtilis
to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that
B. subtilis
L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a
lacZ
-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing).
Comparative Pharmacodynamics of the New Oxazolidinone Tedizolid Phosphate and Linezolid in a Neutropenic Murine Staphylococcus aureus Pneumonia Model
Authors: Lepak Alexander J. , Marchillo Karen , Pichereau Solen , Craig William A. , Andes David R.
Published: September 2012

Tedizolid phosphate (TR-701) is a novel oxazolidinone prodrug (converted to the active form tedizolid [TR-700]) with potent
Staphylococcus aureus
activity. The current studies characterized and compared the
in vivo
pharmacokinetic/pharmacodynamic (PD) characteristics of TR-701/TR-700 and linezolid against methicillin-susceptible
S. aureus
(MSSA) and methicillin-resistant
S. aureus
(MRSA) in the neutropenic murine pneumonia model. The pharmacokinetic properties of both drugs were linear over a dose range of 0.625 to 40 mg/kg of body weight. Protein binding was 30% for linezolid and 85% for TR-700. Mice were infected with one of 11 isolates of
S. aureus
, including MSSA and community- and hospital-acquired MRSA strains. Each drug was administered by oral-gastric gavage every 12 h (q12h). The dosing regimens ranged from 1.25 to 80 mg/kg/12 h for linezolid and 0.625 to 160 mg/kg/12 h for TR-701. At the start of therapy, mice had 6.24 ± 0.40 log
10
CFU/lungs, which increased to 7.92 ± 1.02 log
10
CFU/lungs in untreated animals over a 24-h period. A sigmoid maximum-effect (
E
max
) model was used to determine the antimicrobial exposure associated with net stasis (static dose [SD]) and 1-log-unit reduction in organism relative to the burden at the start of therapy. The static dose pharmacodynamic targets for linezolid and TR-700 were nearly identical, at a free drug (non-protein-bound) area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) of 19 and 20, respectively. The 1-log-unit kill endpoints were also similar, at 46.1 for linezolid and 34.6 for TR-700. The exposure targets were also comparable for both MSSA and MRSA isolates. These dosing goals support further clinical trial examination of TR-701 in MSSA and MRSA pneumonia.