bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation in elemental stoichiometry and RNA:DNA in four phyla of benthic organisms from coral reefs
Authors: Lovelock Catherine E. , Reef Ruth , Pandolfi John M.
Published: January 2014

The elemental composition of organisms has been linked to traits such as growth rates, through investment of phosphorus (P) in RNA (called the Growth Rate Hypothesis) and through ecological processes such as susceptibility to predation and herbivory.

To test the predictions of the Growth Rate Hypothesis, we assessed the elemental composition and RNA of four phyla of common, co‐occurring benthic coral reef organisms, corals, and green, brown and red macroalgae, whose patterns of dominance are predicted to be strongly influenced by differences in growth and herbivory and thus elemental stoichiometry. We assessed the importance of phylogeny and functional form, two important attributes for predicting the composition of macroalgal communities, on the variation in elemental composition.

Over these widely divergent taxonomic groups of organisms, we found support for links between elemental composition and RNA in tissues. The RNA:DNA in corals was positively correlated with % nitrogen (N) and negatively correlated with carbon (C):N ratios of tissues while RNA:DNA and RNA concentrations in macroalgae were positively correlated with %N, N:P ratios and negatively correlated with C:N ratios. Corals had higher concentrations of P and lower C:P ratios than macroalgae. Among the macroalgal lineages, C:P was higher in the brown algae than in red and green algae. Overall, the variation in elemental composition of macroalgae was relatively low compared with the variation reported for terrestrial plants and similar to that in corals.

Analysis of phylogenetic sources of variation (family and genus) in elemental composition and RNA found that genus accounted for a significant proportion of variation in both corals and macroalgae (15–47%), but the largest source of variation (50–97%) was unexplained by our statistical model and thus likely attributable to species and environmental factors. Although elemental composition of macroalgae did not vary in a way that was consistent with functional form models, genera with larger thalli had higher tissue N than smaller forms and more lineages with greater complexity of form had lower C:P ratios than less complex brown algal lineages.

Our data indicate that the despite relatively low levels of variation in elemental composition compared with terrestrial organisms, elemental stoichiometry varied significantly among coral reef taxa and with the structure of organisms and thus may have potential for predicting variation in growth rates and patterns of consumption on coral reefs.
Community assembly and functional diversity along succession post‐management
Authors: Bhaskar Radika , Dawson Todd E. , Balvanera Patricia
Published: January 2014

Despite extensive development of successional theory, few empirical studies have evaluated whether existing models are applicable to human‐modified landscapes. Seasonally dry tropical forests are experiencing widespread transformation, and represent a critical system to assess in a successional framework to infer the mechanisms that shape assembly of secondary forests post‐management.

We used a functional trait‐based approach to assess changes in community assembly mechanisms along a successional gradient in secondary dry forests of varying stages following abandonment of cattle activity. Nearby old‐growth forests served as an undisturbed comparison. We evaluated whether re‐assembly proceeded consistent with existing theory, in early successional stages via habitat filtering, leading to reduced trait range, and via competitive exclusion in later stages, leading to increased trait evenness. Using three orthogonal traits and two functional diversity indices we tested for evidence of assembly mechanisms along resource axes that may be particularly important to dry forest systems, dynamic changes in habitat filtering and competitive exclusion, and potential legacy effects of management.

We found little support of a progression from habitat filtering to competitive exclusion, with the exception of dispersion patterns for specific leaf area and multi‐variate functional richness. Water availability may underlie species sorting in most stages, as evidenced by range reduction in wood density, and might be a resource particularly important to dry forest assembly. Early successional stages displayed an unexpected pattern of low evenness, which may be due to initial stand composition including remnants and resprouts, a regeneration strategy typical to dry forest species. Beyond influencing initial conditions, management legacy was apparent in advanced secondary forests, which differed in range, even dispersion, and functional richness from old‐growth forests, suggesting the operation of different assembly mechanisms.

The departures from expectations suggest the need to re‐assess successional models to include effects of management legacies on the operation of community assembly mechanisms in human‐modified landscapes, as well as characteristics that distinguish wet and dry forest dynamics.
Linking phenological shifts to species interactions through size‐mediated priority effects
Authors: Rasmussen Nick L. , Van Allen Benjamin G. , Rudolf Volker H. W.
Published: January 2014

Interannual variation in seasonal weather patterns causes shifts in the relative timing of phenological events of species within communities, but we currently lack a mechanistic understanding of how these phenological shifts affect species interactions. Identifying these mechanisms is critical to predicting how interannual variation affects populations and communities.

Species' phenologies, particularly the timing of offspring arrival, play an important role in the annual cycles of community assembly. We hypothesize that shifts in relative arrival of offspring can alter interspecific interactions through a mechanism called size‐mediated priority effects (SMPE), in which individuals that arrive earlier can grow to achieve a body size advantage over those that arrive later.

In this study, we used an experimental approach to isolate and quantify the importance of SMPE for species interactions. Specifically, we simulated shifts in relative arrival of the nymphs of two dragonfly species to determine the consequences for their interactions as intraguild predators.

We found that shifts in relative arrival altered not only predation strength but also the nature of predator–prey interactions. When arrival differences were great, SMPE allowed the early arriver to prey intensely upon the late arriver, causing exclusion of the late arriver from nearly all habitats. As arrival differences decreased, the early arriver's size advantage also decreased. When arrival differences were smallest, there was mutual predation, and the two species coexisted in similar abundances across habitats. Importantly, we also found a nonlinear scaling relationship between shifts in relative arrival and predation strength. Specifically, small shifts in relative arrival caused large changes in predation strength while subsequent changes had relatively minor effects.

These results demonstrate that SMPE can alter not only the outcome of interactions but also the demographic rates of species and the structure of communities. Elucidating the mechanisms that link phenological shifts to species interactions is crucial for understanding the dynamics of seasonal communities as well as for predicting the effects of climate change on these communities.
Greater migratory propensity in hosts lowers pathogen transmission and impacts
Authors: Hall Richard J. , Altizer Sonia , Bartel Rebecca A.
Published: January 2014

Animal migrations are spectacular and migratory species have been shown to transmit pathogens that pose risks to human health. Although migration is commonly assumed to enhance pathogen dispersal, empirical work indicates that migration can often have the opposite effect of lowering disease risk.

Key to assessing disease threats to migratory species is the ability to predict how migratory behaviour influences pathogen invasion success and impacts on migratory hosts, thus motivating a mechanistic understanding of migratory host–pathogen interactions.

Here, we develop a quantitative framework to examine pathogen transmission in animals that undergo two‐way directed migrations between wintering and breeding grounds annually.

Using the case of a pathogen transmitted during the host's breeding season, we show that a more extreme migratory strategy (defined by the time spent away from the breeding site and the total distance migrated) lowers the probability of pathogen invasion. Moreover, if migration substantially lowers the survival probability of infected animals, then populations that spend comparatively less time at the breeding site or that migrate longer distances are less vulnerable to pathogen‐induced population declines.

These findings provide theoretical support for two non‐exclusive mechanisms proposed to explain how seasonal migration can lower infection risk: (i) escape from habitats where parasite transmission stages have accumulated and (ii) selective removal of infected hosts during strenuous journeys. Our work further suggests that barriers to long‐distance movement could increase pathogen prevalence for vulnerable species, an effect already seen in some animal species undergoing anthropogenically induced migratory shifts.
Using dynamic Brownian bridge movement modelling to measure temporal patterns of habitat selection
Authors: Byrne Michael E. , Clint McCoy J. , Hinton Joseph W. , Chamberlain Michael J. , Collier Bret A.
Published: January 2014

Accurately describing animal space use is vital to understanding how wildlife use habitat. Improvements in GPS technology continue to facilitate collection of telemetry data at high spatial and temporal resolutions. Application of the recently introduced dynamic Brownian bridge movement model (dBBMM) to such data is promising as the method explicitly incorporates the behavioural heterogeneity of a movement path into the estimated utilization distribution (UD).

Utilization distributions defining space use are normally estimated for time‐scales ranging from weeks to months, obscuring much of the fine‐scale information available from high‐volume GPS data sets. By accounting for movement heterogeneity, the dBBMM provides a rigorous, behaviourally based estimate of space use between each set of relocations. Focusing on UDs generated between individual sets of locations allows us to quantify fine‐scale circadian variation in habitat use.

We used the dBBMM to estimate UDs bounding individual time steps for three terrestrial species with different life histories to illustrate how the method can be used to identify fine‐scale variations in habitat use. We also demonstrate how dBBMMs can be used to characterize circadian patterns of habitat selection and link fine‐scale patterns of habitat use to behaviour.

We observed circadian patterns of habitat use that varied seasonally for a white‐tailed deer (Odocoileus virginianus) and coyote (Canis latrans). We found seasonal patterns in selection by the white‐tailed deer and were able to link use of conifer forests and agricultural fields to behavioural state of the coyote. Additionally, we were able to quantify the date in which a Rio Grande wild turkey (Meleagris gallopavo intermedia) initiated laying as well as when during the day, she was most likely to visit the nest site to deposit eggs.

The ability to quantify circadian patterns of habitat use may have important implications for research and management of wildlife. Additionally, the ability to link such patterns to behaviour may aid in the development of mechanistic models of habitat selection.
Immigrants are attracted by local pre‐breeders and recruits in a seabird colony
Authors: Szostek K. Lesley , Schaub Michael , Becker Peter H.
Published: January 2014

Immigration is a major demographic factor shaping population dynamics. However, due to methodological difficulties, the extent of immigration and factors affecting immigration are insufficiently studied. This is also true for seabird colonies.

We estimated annual immigration based on a long‐term study of a colony of common ternsSterna hirundomarked with transponders, using a Bayesian integrated population model that links colony size and productivity with individual life histories.

Strong annual fluctuations in the number of immigrants were found. To identify whether colony‐specific covariates influenced immigration, we related the number of immigrants to various proxy variables for breeding site quality, specifically colony size, productivity, number of local subadults and local recruits. Numbers of local recruits and local subadults showed strong positive correlations with number of immigrants.

We found that variation in immigration rate had strongly contributed to variation in colony growth rate, more so than variation in local recruitment or adult survival.

Collectively, results suggest that immigration strongly affects colony growth rate, that the driving force behind immigration is natal dispersal and that immigrants were attracted by local recruits.
Pyridostigmine prevents peripheral vascular endothelial dysfunction in rats with myocardial infarction
Authors: Qin Fangfang , Lu Yi , He Xi , Zhao Ming , Bi Xueyuan , Yu Xiaojiang , Liu Jinjun , Zang Weijin
Published: January 2014

Myocardial infarction (MI) is characterized by the withdrawal of vagal activity and increased sympathetic activity. We have shown previously that pyridostigmine (PYR), an acetylcholinesterase inhibitor, was able to improve vagal activity and ameliorate cardiac dysfunction following MI. However, the effect of PYR on endothelial dysfunction in peripheral arteries after MI remains unclear.

In the present study, MI was induced by coronary artery ligation in adult Sprague–Dawley rats. Rats were treated intragastrically with saline or PYR (approximately 31 mg/kg per day) for 2 weeks, at which time haemodynamic and parasympathetic parameters and the vascular reactivity of isolated mesenteric arteries were measured and the ultrastructure of the endothelium evaluated.

Compared with the MI group, PYR not only improved cardiac function, vagal nerve activity and endothelial impairment, but also reduced intravascular superoxide anion and malondialdehyde. In addition, in the PYR‐treated MI group, nitric oxide (NO) bioavailability was increased and attenuated endothelium‐dependent relaxations were improved, whereas restored vasodilator responses were inhibited by NG‐nitro‐l‐arginine methyl ester.

Based on our results, PYR is able to attenuate the impairment of peripheral endothelial function and maintain endothelial ultrastructural integrity in MI rats by inhibiting reactive oxygen species production, enhancing NO bioavailability and improving vagal activity.
Calorie restriction upregulated sirtuin 1 by attenuating its ubiquitin degradation in cancer cells
Authors: Han Limin , Zhao Ganye , Wang Hui , Tong Tanjun , Chen Jun
Published: January 2014

Sirtuin (SIRT) 1 is a key protein in mediating the benefits of calorie restriction (CR) in mammals. However, the molecular mechanisms underlying CR‐induced SIRT1 upregulation in mammals remain unclear. Herein we show that the elevated SIRT1 levels are not due to increased SIRT1 mRNA expression. but rather to enhanced SIRT1 protein stability as a result of reduced ubiquitin‐proteasome degradation of SIRT1 under limited nutrient conditions. Our observations have important implications for improving healthy aging in humans.
Additional role of serum 25‐hydroxyvitamin D3 levels in atherosclerosis in Chinese middle‐aged and elderly men
Authors: Hao Yaping , Ma Xiaojing , Luo Yuqi , Ni Jie , Dou Jianxin , Zhu Jiaan , Bao Yuqian , Jia Weiping
Published: January 2014

Perturbed serum vitamin D levels have been shown to be associated with increased risk of cardiovascular disease. The aim of the present study was to investigate the association of serum 25‐hydroxyvitamin D3 (25(OH)D3) levels and B ultrasonography‐detected carotid plaque and carotid intima–media thickness (C‐IMT) in Chinese middle‐aged and elderly men.

In all, 1001 men, aged 45–78 years, were enrolled in the study. Increased C‐IMT was defined as any C‐IMT value in the highest quartile of the study subjects (≥ 0.75 mm).

The study population had a median serum 25(OH)D3 level of 14.51 ng/mL (interquartile range (IQR) 10.84–18.67 ng/mL). Subjects with carotid plaques had lower serum 25(OH)D3 levels than those without (13.80 (IQR 10.82–17.68) vs 14.74 (IQR 10.87–19.08) ng/mL, respectively; P = 0.029), and decreasing serum 25(OH)D3 levels were accompanied by increased C‐IMT in both groups (13.24 (IQR 9.91–16.81) vs 14.45 (IQR 11.40–18.51) ng/mL, respectively (P < 0.05) in those with plaque; 13.80 (IQR 9.99–17.09) vs 14.99 (IQR 11.17–19.43) ng/mL, respectively (P < 0.01) in those without plaque). Multivariate logistic regression analysis showed that serum 25(OH)D3 levels were independently associated with carotid plaque (odds ratio (OR) 0.972; 95% confidence interval (CI) 0.946–0.998; P = 0.032). In addition, serum 25(OH)D3 levels were identified as an independent protective factor for increased C‐IMT among subjects with plaque (OR 0.900; 95% CI 0.849–0.955; P = 0.001) and those without plaque (OR 0.944; 95% CI 0.908–0.981; P = 0.004).

Collectively, these findings suggest that serum 25(OH)D3 levels are inversely associated with atherosclerosis in Chinese middle‐aged and elderly men.
Increased polymerase I and transcript release factor (Cavin‐1) expression attenuates platelet‐derived growth factor receptor signalling in senescent human fibroblasts
Authors: Li Qian , Bai Lin , Liu Ning , Wang Miao , Liu Jun‐Ping , Liu Pingsheng , Cong Yu‐Sheng
Published: January 2014

Previously, we showed that the essential caveolar component polymerase I and transcript release factor (PTRF) was upregulated and promoted caveolae formation in senescent cells. In addition, we found that overexpression of PTRF increased the number of caveolae and induced cellular senescence.

Unresponsiveness to growth factor is one of the fundamental characteristics of senescent cells, although normal levels of receptors and downstream signalling molecules are present in senescent cells.

Herein, we investigated the role of PTRF in the regulation of platelet‐derived growth factor (PDGF) signalling in young and senescent cells.

We first confirmed that PTRF was upregulated in senescent human fibroblasts and aged mouse tissues. We then examined the activation of extracellular signal‐regulated kinases (ERK) in young and senescent cells after PDGF stimulation.

Our results show that expression of PDGF receptors (PDGFRs) was not altered during cellular senescence. Interestingly, phosphorylation of ERK1/2 was induced upon PDGF stimulation of young, replicating cells but not senescent cells. Induction of ERK1/2 phosphorylation was impaired in senescent cells and PTRF‐overexpressing presenescent cells. Furthermore, our results show that PTRF interacts with PDGFRs and this interaction is increased in senescent cells.

These results suggest that the unresponsiveness of senescent fibroblasts to PDGF stimulation may be due to increased levels of PTRF and the formation of caveolae, which, in turn sequester growth receptors, such as PDGFR and its signalling molecules.
Aerobic interval training protects against myocardial infarction‐induced oxidative injury by enhancing antioxidase system and mitochondrial biosynthesis
Authors: Jiang Hong‐Ke , Miao Yi , Wang You‐Hua , Zhao Mei , Feng Zhi‐Hui , Yu Xiao‐Jiang , Liu Jian‐Kang , Zang Wei‐Jin
Published: January 2014

Aerobic interval training (AIT) exerts beneficial effects on cardiovascular disease. However, its cardioprotective mechanisms are not fully understood. The aim of the present study was to evaluate AIT‐mediated anti‐oxidation by focusing on anti‐oxidase and mitochondrial biogenesis in rats after myocardial infarction (MI).

Sprague–Dawley rats were divided into three groups: (i) a sham‐operated control (CON); (ii) an MI group; and (iii) an MI + AIT group. Myocardial microstructure and function, markers of oxidative stress, mitochondrial anti‐oxidase, Phase II enzymes and mitochondrial biogenesis were assessed. In addition, levels of nuclear factor‐erythroid 2‐related factor (Nrf2) and phosphorylated (p‐) AMP‐activated protein kinase (AMPK) were determined. The anti‐oxidative gene sirtuin 3 (SIRT3) and the prosurvival phosphatidylinositol‐3 kinase (PI3‐K)‐protein kinase B (Akt) signalling cascade were also evaluated.

Compared with CON, there was noticeable microstructure injury, cardiac dysfunction and oxidative damage in rats after MI. In addition, decreased mitochondrial anti‐oxidase content, Phase II enzyme (except heme oxygenase‐1) expression and mitochondrial biogenesis were observed in the post‐MI rats as well as reduced protein levels of the regulators Nrf2 and p‐AMPK and suppression of SIRT3 levels and PI3‐K/Akt signalling. These detrimental modifications were considerably ameliorated by AIT, as evidenced by increases in anti‐oxidase, mitochondrial biogenesis, Nrf2 and AMPK phosphorylation, as well as SIRT3 upregulation and PI3‐K/Akt signalling activation. Moreover, PI3‐K inhibitor‐LY294002 (20 mg/kg) treatment partly attenuated AIT‐elicited increases in Nrf2 levels and AMPK phosphorylation.

Based on these results, we conclude that AIT effectively alleviates MI‐induced oxidative injury, which may be closely correlated with activation of the anti‐oxidase system and mitochondrial biosynthesis. Increased SIRT3 expression and activation of PI3‐K/Akt signalling may play key roles in AIT‐mediated anti‐oxidation. These results open up new avenues for exercise intervention therapies for MI patients.
Involvement of purinergic receptors and NOD‐like receptor‐family protein 3‐inflammasome pathway in the adenosine triphosphate‐induced cytokine release from macrophages
Authors: Gicquel Thomas , Victoni Tatiana , Fautrel Alain , Robert Sacha , Gleonnec Florence , Guezingar Marie , Couillin Isabelle , Catros Véronique , Boichot Elisabeth , Lagente Vincent
Published: January 2014

Adenosine triphosphate (ATP) has been described as a danger signal activating the NOD‐like receptor‐family protein 3 (NLRP3)‐inflammasome leading to the pro‐inflammatory cytokine, interleukin (IL)‐1β, release in the lung. The NLRP3‐inflammasome pathway has been previously described to be involved in experimental collagen deposition and the development of pulmonary fibrosis.

The aim of the present study was to investigate the role of the NLRP3 inflammasome pathway and P2X7 purinergic receptor in the activation of human macrophages in vitro by ATP.

We showed that adenosine 5′‐[γ‐thio]triphosphate tetralithium salt (ATPγS) and 2′,3′‐O‐(4‐benzoylbenzoyl) adenosine 5′‐triphosphate (BzATP), two stable analogs of ATP, are able to potentiate the release of IL‐1β from human monocyte‐derived macrophages induced by low concentration of lipopolysaccharide (LPS). However, in the same conditions no increase in IL‐1α and IL‐6 was observed. Immunochemistry has shown that human macrophages natively express NLRP3 and purinergic P2X7 receptors (P2X7R). NLRP3 and IL‐1β mRNA expression were induced from LPS‐primed macrophages, but also after 5‐h treatment of BzATP as analysed by reverse transcription quantitative polymerase chain reaction. However, other inflammasome pathways (NLRP1, NLRP2, NLRC4, NLRP6 and AIM2) and P2X7R were not induced by BzATP. We observed that P2X7R antagonists, A‐438079 and A‐740003, were able to reduce the release of IL‐1β, but not of IL‐1α and IL‐6 from macrophages stimulated by ATPγS or BzATP.

The present results showed the involvement of the P2X7R‐NLRP3 inflammasome pathway in the secretion of IL‐1β from ATP‐stimulated human macrophages, and suggest that P2X7R were not involved in IL‐1α and IL‐6 release. This study also points out that repression of the P2X7R represents a novel potential therapeutic approach to control fibrosis in lung injury.
Effects of Spirogyra arcta on biomass and structure of submerged macrophyte communities
Authors: Dong Bi‐Cheng , Liu Rui‐Hua , Yu Fei‐Hai
Published: January 2014

The presence of algae can greatly reduce the amount of light that reaches submerged macrophytes, but few experimental studies have been conducted to examine the effects of algae on biomass and structure of submerged macrophyte communities. We constructed communities with four submerged macrophytes (Hydrilla verticillata, Egeria densa, Ceratophyllum demersum, and Chara vulgaris) in three environments in which 0 (control), 50 and 100% of the water surface was covered by Spirogyra arcta. Compared to the control treatment, the 100% spirogyra treatment decreased biomass of the submerged macrophyte communities and of all the four macrophytes except C. demersum. Compared to the control and 50% treatments, the 100% treatment significantly increased relative abundance of C. demersum and decreased that of E. densa. Therefore, the presence of S. arcta can greatly affect the productivity and alter the structure of submerged macrophyte communities. To restore submerged macrophyte communities in conditions with abundant algae, assembling communities consisting of C. demersum or similar species may be a good practice.
Poo wars as matter out of place: ‘Toilets for Africa’ in Cape Town (Respond to this article at http://www.therai.org.uk/at/debate)
Authors: Robins Steven
Published: January 2014

In this editorial the author looks at poo protests in South Africa as political in various ways, comparing it to the Great Stink of London in the 19th century.
Social media and the transformation of ‘Chinese nationalism’: ‘Igniting positive energy’ in China since the 2012 London Olympics (Respond to this article at http://www.therai.org.uk/at/debate)
Authors: Du Shanshan
Published: January 2014

During the 2012 London Olympics, a spontaneous movement to ‘ignite positive energy’ emerged in Chinese social media from the massive and fervent support for the Chinese grassroots torch bearers. This grassroots‐oriented movement has generated a ‘transcendental Chinese patriotism’, in which patriotism is intertwined with individualism, transnationalism, and universalism. The ideal and sentiment of this hybrid Chinese patriotism forms a stark contrast to the mainstream ‘Chinese nationalism’, which has been characterized by scholars as various forms of reactive collectivism derived from state authority, Confucian tradition, and the wounded memories of China's recent history. This online movement has also demonstrated an impressive efficacy in shaping the socio‐political landscape of China beyond transforming Chinese nationalism.
Dog Waste, Wasted Dogs: The Contribution of Human–Dog Relations to the Political Ecology of Australian Urban Space
Authors: INSTONE LESLEY , SWEENEY JILL
Published: January 2014

The city is increasingly recognised as a complex more‐than‐human space where the lives of humans and non‐humans entwine in consequential ways. Human–animal encounters constitute sometimes convivial and sometimes challenging relations that reflect wider pleasures and tensions in urban society. This paper grapples with concerns about the place of dogs in Australian urban public space and urban life more broadly. Adopting a relational political ecology approach, we ask what pet dogs tell us about the political, emotional, and material struggles that surround multispecies urban cohabitation. Following two human–dog urban waste streams – one concerned with dog waste, the other with dogs as waste – we consider how human–animal relations of both attachment and disposability shape the material flows that constitute urban political ecologies. In particular, by focusing on the ‘shadow ecologies’ of dog waste and disposal, we uncover the dynamic practices of care, disgust, violence, and love through which dogs, their waste, and their bodies are sanitised, controlled, and ultimately concealed from our everyday urban spaces.
An allopurinol‐controlled, multicenter, randomized, double‐blind, parallel between‐group, comparative study of febuxostat in Chinese patients with gout and hyperuricemia
Authors: Huang Xinfang , Du Hui , Gu Jieruo , Zhao Dongbao , Jiang Lindi , Li Xinfu , Zuo Xiaoxia , Liu Yi , Li Zhanguo , Li Xiangpei , Zhu Ping , Li Juan , Zhang Zhiyi , Huang Anbin , Zhang Yuanchao , Bao Chunde
Published: January 2014

Aim

Febuxostat, a novel non‐purine selective inhibitor of xanthine oxidase, has been identified as a potential alternative to allopurinol in patients with hyperuricemia. The purpose of this study was to compare the urate‐lowering (UL) efficacy and safety of daily febuxostat and allopurinol in Chinese gout patients with hyperuricemia.

Methods

Gout patients (n = 512) with serum uric acid (sUA) concentrations of at least 8.0 mg/dL were randomized to receive daily febuxostat 40 mg or 80 mg or allopurinol 300 mg for 28 weeks. Prophylaxis against gout flares with meloxicam or colchicine was provided during weeks 1 through 8. The primary endpoint was the percentage of subjects achieving a sUA concentration of <6.0 mg/dL at the last three monthly measurements.

Results

The primary endpoint was reached in 44.77% of patients receiving 80 mg of febuxostat, 27.33% of those receiving 40 mg of febuxostat, and 23.84% of those receiving allopurinol. The UL efficacy in the febuxostat 80 mg group was higher than in the allopurinol (P < 0.0001) and febuxostat 40 mg (P = 0.0008) groups. The UL efficacy of the febuxostat 40 mg group was statistically non‐inferior to that of the allopurinol group. No significant change in the number of tophi was observed during the final visit relative to baseline in each treatment group. The rate of gout flares requiring treatment from weeks 9 through 28 and the incidence of adverse events was similar among treatment groups.

Conclusions

The UL efficacy of daily febuxostat 80 mg was greater than that of febuxostat 40 mg and allopurinol 300 mg, which exhibited comparable UL efficacy. Safety of febuxostat and allopurinol was comparable at the doses tested.
Ministerial Responsiveness in Westminster Systems: Institutional Choices and House of Commons Debate, 1832–1915
Authors: Eggers Andrew C. , Spirling Arthur
Published: January 2014

In Westminster systems, governments enjoy strong agenda‐setting powers but are accountable to an inquisitorial opposition. This article provides insights into the origins of this arrangement from the British House of Commons, drawing primarily on a new data set of a half million parliamentary speeches. We show that, according to a novel measure we develop, government ministers became more responsive to opposition members of parliament in the same period that the government's agenda power was most conclusively strengthened—roughly, the two decades culminating in Balfour's “railway timetable” of 1902. We argue that this increase in responsiveness helps to explain why opposition members of parliament acceded to reductions in their procedural power. We thus highlight a link between government strength and opposition scrutiny in the historical development of the Westminster system.
Serum 25‐hydroxyvitamin D levels and self‐reported allergic rhinitis in Norwegian adults – The HUNT Study
Authors: Mai X.‐M. , Chen Y. , Camargo C. A. , Langhammer A.
Published: January 2014

Background

The role of low vitamin D status in the development of allergic rhinitis is unclear. We aimed to investigate the relationship between serum 25‐hydroxyvitamin D [25(OH)D] and incidence of allergic rhinitis in adults.

Methods

The study included a random sample from an adult population who participated in the second and third surveys of the Nord‐Trøndelag Health Study (HUNT) in Norway (HUNT2, 1995–1997 and HUNT3, 2006–2008). Serum 25(OH)D levels were measured in blood samples collected at baseline. Among 1351 adults who did not report allergic rhinitis at baseline, incident allergic rhinitis was identified by participant report of having or having had allergic rhinitis or hay fever at follow‐up. Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated after adjustment for age, smoking, physical activity, socioeconomic status, family history of allergy, body mass index, and season. The analyses were stratified by sex due to its significant interaction with 25(OH)D levels (P < 0.02).

Results

Over an average of 11 years, 9% of men and 15% of women developed allergic rhinitis. Among men, serum 25(OH)D level <50 nM was associated with an increased risk of incident allergic rhinitis (AOR 2.55; 95% CI 1.01–6.49); each 25 nM reduction in 25(OH)D level was associated with an AOR of 1.84 (95% CI 1.18–2.87). In women, however, the association was opposite, with AOR being 0.83 (95% CI 0.66–1.05) for each 25 nM reduction in serum 25(OH)D level.

Conclusions

Vitamin D appears to play different roles in the development of allergic rhinitis among men and women.
Narcissism and Counterproductive Work Behavior (CWB): Meta‐Analysis and Consideration of Collectivist Culture, Big Five Personality, and Narcissism's Facet Structure
Authors: Grijalva Emily , Newman Daniel A.
Published: January 2014

A recent review of the relationship between narcissism and CWB reported two key results: (a) narcissism is the dominant predictor of CWB among the dark triad personality traits, and (b) the narcissism–CWB relationship is moderated by ingroup collectivist culture (k = 9; N = 2,708; O'Boyle, Forsyth, Banks, & McDaniel, 2012). The current work seeks to enhance understanding of the narcissism–CWB relationship in five ways. First, we update O'Boyle et al.'s (2012) meta‐analysis to include over 50 per cent more data (k = 16; N = 4,424), and demonstrate that narcissism remains the largest unique predictor of CWB after controlling for the Big Five personality traits. Second, we reveal that O'Boyle and colleagues' inference of cross‐cultural moderation hinges on a single dataset from Bangladesh. Third, based on an original international dataset of on‐line respondents, we reaffirm that ingroup collectivist culture does moderate/weaken the narcissism–CWB relationship. Fourth, we show that the narcissism–CWB relationship is stronger in published (corrected r = .48) versus unpublished studies (corrected r = .15). Finally, we propose a new moderator of the narcissism–CWB relationship: narcissism's facets. One facet (Entitlement/Exploitativeness) relates positively to CWB, whereas another facet of narcissism (Leadership/Authority) relates negatively to CWB.
Voltage‐operated Ca2+ currents and Ca2+‐activated Cl– currents in single interstitial cells of the guinea‐pig prostate
Authors: Lang Richard J. , Tonta Mary A. , Takano Hiromichi , Hashitani Hikaru
Published: January 2014

Objective

To investigate the expression of ‘T‐type’ and ‘L‐type’ voltage‐operated Ca2+ channels in single interstitial cells of the guinea‐pig prostate.

Material and Methods

Whole‐cell and perforated patch‐clamp techniques were applied to prostatic interstitial cells (PICs) dispersed using collagenase.

Results

In contrast to prostatic myocytes, PICs under voltage clamp and filled with K+ (130 mm) were distinguished by the absence of a voltage‐operated transient outward K+ current or spike discharge upon membrane depolarisation when under current clamp. Depolarisation of Cs+‐filled PICs evoked an inward current at potentials positive to −60 mV, which peaked in amplitude near 0 mV. This inward current increased when Ba2+ (5 mm) replaced the external Ca2+ (1.5 mm) and displayed a variable sensitivity to the inhibitory actions of conditioning depolarisations to −40 mV applied before the test depolarisation or to 1 μm nifedipine, the ‘L‐type’ Ca2+ channel blocker. A residual inward current recorded in nifedipine was blocked by 10 μm Ni2+. Cs+‐filled PICs also displayed a slowly inactivating outward current that was little affected by nifedipine, reduced by the Cl– channel blocker, niflumic acid (10 μm) and blocked by Ba2+ or a conditioning depolarisation.

Conclusion

PICs express both a small ‘T‐type’ Ca2+ channel current (ICa) and a large ‘L‐type’ ICa. Ca2+ influx through ‘T‐type’ ICa was an essential trigger for the activation of a Ca2+‐activated Cl–‐selective current. The dependence of PIC Ca2+ signalling on ‘T‐type’ and ‘L‐type’ ICa is unique compared with other interstitial cells of the urogenital tract and may well be pharmaceutically exploitable.
Sex differences in endothelial function in porcine coronary arteries: a role for H2O2 and gap junctions?
Authors: Wong P S , Roberts R E , Randall M D
Published: January 2014

Background and Purpose

Cardiovascular risk is higher in men and postmenopausal women compared with premenopausal women. This may be due to sex differences in endothelial function. Here, sex differences in endothelial function of porcine coronary arteries (PCAs) were investigated.

Experimental Approach

Distal PCAs were studied under myographic conditions and after precontraction with U46619. Concentration‐response curves to bradykinin were constructed in the presence of a range of inhibitors.

Key Results

In male and female PCAs, bradykinin produced comparable vasorelaxant responses. Inhibition of NO and prostanoid synthesis produced greater inhibition in males compared with females. Removing H2O2 with PEG‐catalase reduced the maximum relaxation in the absence, but not the presence of L‐NAME and indomethacin in females, and had no effect in males. Blocking gap junctions with 100 µM carbenoxolone or 18α‐glycyrrhetinic acid further inhibited the endothelium‐derived hyperpolarization (EDH)‐mediated response in females but not in males. In female PCAs, the maximum EDH‐mediated response was reduced by inhibiting SKCa with apamin and by inhibiting IKCa with TRAM‐34, or with both. In male PCAs, at maximum bradykinin concentration, the EDH‐mediated response was reduced in the presence of apamin but not TRAM‐34. Western blot did not detect any differences in connexins 40 or 43 or in IKCa expression between male and female PCAs.

Conclusions and Implications

H2O2 mediated some part of endothelium‐dependent vasorelaxation in female PCAs and EDH was more important in females, with differences in the contribution of gap junctions and IKCa channels. These findings may contribute to understanding vascular protection in premenopausal women.
Heart ischaemia–reperfusion induces local up‐regulation of vasoconstrictor endothelin ETB receptors in rat coronary arteries downstream of occlusion
Authors: Skovsted G F , Kruse L S , Larsen R , Pedersen A F , Trautner S , Sheykhzade M , Edvinsson L
Published: January 2014

Background and Purpose

Endothelins act via two receptor subtypes, ETA and ETB. Under physiological conditions in coronary arteries, ETA receptors expressed in smooth muscle cells mediate vasoconstriction whereas ETB receptors mainly found in endothelial cells mediate vasorelaxation. However, under pathophysiological conditions, ETB receptors may also be expressed in vascular smooth muscle cells mediating vasoconstriction. Here, we have investigated whether vasoconstrictor ETB receptors are up‐regulated in coronary arteries after experimental myocardial ischaemia in rats.

Experimental Approach

Male Sprague‐Dawley rats were subjected to either heart ischaemia–reperfusion (15 min ischaemia and 22 h reperfusion), permanent ischaemia (22 h) by ligation of the left anterior descending coronary artery, or sham operation. Using wire myography, the endothelin receptor subtypes mediating vasoconstriction were examined in isolated segments of the left anterior descending and the non‐ligated septal coronary arteries. Endothelin receptor‐mediated vasoconstriction was examined with cumulative administration of sarafotoxin 6c (ETB receptor agonist) and endothelin‐1 (with or without ETA or ETB receptor blockade). The distribution of ETB receptors was localized with immunohistochemistry and quantified by Western blot.

Key Results

Endothelin ETB receptor‐mediated vasoconstriction and receptor protein levels were significantly augmented in coronary arteries situated downstream of the occlusion after ischaemia–reperfusion compared with non‐ischaemic arteries. In contrast, the ETA receptor‐mediated vasoconstriction was unaltered in all groups.

Conclusions and Implications

Ischaemia–reperfusion induced local up‐regulation of ETB receptors in the smooth muscle cells of coronary arteries in the post‐ischaemic area. In contrast, in non‐ischaemic areas, ETB receptor function was unaltered.
Luteolin is effective in the non‐small cell lung cancer model with L858R/T790M EGF receptor mutation and erlotinib resistance
Authors: Hong Zhuan , Cao Xiang , Li Na , Zhang Yizhou , Lan Lei , Zhou Yi , Pan Xiaolong , Shen Lei , Yin Zhimin , Luo Lan
Published: January 2014

Background and Purpose

Non‐small cell lung cancer (NSCLC) is one of the most commonly diagnosed malignancies in the world. Small‐molecule inhibitors of the EGF receptor's tyrosine kinase domain (TKIs), including gefitinib and erlotinib, have been widely used for treating NSCLC. Unfortunately, nearly all patients after initially experiencing a marked improvement while on these drugs, eventually progress to acquire resistance to TKIs. Because there is no effective therapeutic strategy to treat TKI‐resistant NSCLC, we evaluated the effects of luteolin, a naturally occurring flavanoid, on T790M mutant NSCLC cells.

Experimental Approach

The effect of luteolin on the viability of NSCLC and normal cell lines was investigated using the Cell Counting Kit‐8 (CCK‐8) assay. Luteolin‐induced apoptosis was assessed by bivariate FITC‐annexin V/PI assay, and Western blots were used to measured apoptotic proteins. Co‐immunoprecipitation was used to determine the effect of luteolin on the interaction between Hsp90 and mutant EGF receptors. The effect of luteolin on the Akt/mTOR pathway was studied using Western blotting analysis. Its anti‐tumour efficacy in vivo was examined in a mouse xenograft model.

Key Results

Luteolin exerted significant anti‐tumourigenic effects on the EGF receptor L858R/T790M mutation and erlotinib‐resistant NSCLC both at the cellular and animal levels. Mechanistically, luteolin induced degradation of the EGF receptor by inhibiting the association of Hsp90 with the mutant EGF receptor, and, therefore, prevented PI3K/Akt/mTOR signalling, which resulted in NSCLC cell apoptosis.

Conclusion and Implications

Luteolin may be a potential candidate for NSCLC therapy, especially for treatment of patients with acquired erlotinib‐resistant NSCLC.
Psychiatric disease in late adolescence and young adulthood. Foetal programming by maternal hypothyroidism?
Authors: Andersen Stine Linding , Olsen Jørn , Wu Chun Sen , Laurberg Peter
Published: January 2014

Objective

Lack of maternal thyroid hormones during foetal brain development may lead to structural abnormalities in the brain. We hypothesized that maternal hypothyroidism during the pregnancy could programme the foetus to development of psychiatric disease later in life.

Design

Danish nationwide register study.

Participants

Singletons live‐born 1980–1990.

Measurements

Cox proportional hazards model was used to estimate adjusted hazard ratio (aHR) with 95% confidence interval for offspring redemption of ≥2 prescriptions of a psychiatric drug from age 15 to 31 years.

Results

Among 542 100 adolescents and young adults included, altogether 3979 (0·7%) were born to mothers with hypothyroidism registered before 1996. In crude analyses, the use of a psychiatric drug was more frequent in late adolescence and young adulthood when the mother had hypothyroidism (P < 0·001); however, several possible confounders had to be taken into account. For example, mothers with hypothyroidism often also had a psychiatric registration (38·5% vs 27·7%, P < 0·001) and the use of psychiatric drugs changed over time. After adjustment for confounders including birth year, maternal age and maternal psychiatric history, maternal hypothyroidism was associated with an increased risk of having redeemed prescriptions of anxiolytics [aHR 1·23 (1·03–1·48)] and antipsychotics [aHR 1·22 (1·03–1·44)] in late adolescence and young adulthood. For antidepressants, aHR was 1·07 (0·98–1·17).

Conclusions

The association between maternal hypothyroidism and the use of a psychiatric drug in late adolescence and young adulthood was partly confounded by maternal psychiatric history, but foetal programming by maternal hypothyroidism may be part of the mechanisms leading to the use of anxiolytics and antipsychotics.
One and Done? Optimal Decisions From Very Few Samples
Authors: Vul Edward , Goodman Noah , Griffiths Thomas L. , Tenenbaum Joshua B.
Published: January 2014

In many learning or inference tasks human behavior approximates that of a Bayesian ideal observer, suggesting that, at some level, cognition can be described as Bayesian inference. However, a number of findings have highlighted an intriguing mismatch between human behavior and standard assumptions about optimality: People often appear to make decisions based on just one or a few samples from the appropriate posterior probability distribution, rather than using the full distribution. Although sampling‐based approximations are a common way to implement Bayesian inference, the very limited numbers of samples often used by humans seem insufficient to approximate the required probability distributions very accurately. Here, we consider this discrepancy in the broader framework of statistical decision theory, and ask: If people are making decisions based on samples—but as samples are costly—how many samples should people use to optimize their total expected or worst‐case reward over a large number of decisions? We find that under reasonable assumptions about the time costs of sampling, making many quick but locally suboptimal decisions based on very few samples may be the globally optimal strategy over long periods. These results help to reconcile a large body of work showing sampling‐based or probability matching behavior with the hypothesis that human cognition can be understood in Bayesian terms, and they suggest promising future directions for studies of resource‐constrained cognition.