bluuebunny/crossref_metadata_2025 huggingface dataset:
Irsogladine maleate inhibits Porphyromonas gingivalis‐mediated expression of toll‐like receptor 2 and interleukin‐8 in human gingival epithelial cells
Authors: Savitri I. J. , Ouhara K. , Fujita T. , Kajiya M. , Miyagawa T. , Kittaka M. , Yamakawa M. , Shiba H. , Kurihara H.
Published: September 2014

Background and Objective

Periodontitis is an infectious disease caused by an interaction between the host and periodontopathogenic bacteria. Regulating the immune response in human gingival epithelial cells (HGEC) may contribute to the prevention of periodontitis. Irsogladine maleate (IM) has previously been shown to regulate inflammation and the cell–cell junctional barrier in HGEC. In addition to these functions, control of bacterial recognition is important for preventing inflammation in periodontal tissue. Innate immunity in gingival epithelium is the first line of defense and plays a crucial role against bacterial challenge. Therefore, the effect of IM on regulating toll‐like receptor 2 (TLR2), which is part of the innate immunity, was determined in this study.

Material and Methods

OBA‐9, an immortalized human gingival epithelial cell line, and primary cultured HGEC were used in this study. Real‐time PCR and western blotting were performed in OBA‐9 or HGEC stimulated with whole cells of Porphyromonas gingivalis or with lipopolysaccharide (LPS) derived from P. gingivalis (PgLPS) in the presence or absence of IM to determine expression of TLR2 mRNA and production of TLR2 protein. Small interfering RNA (siRNA) against TLR2 was transfected into OBA‐9 to clarify the association between the induction of TLR2 and interleukin‐8 (IL‐8) production.

Results

The addition of IM into P. gingivalis or PgLPS‐induced OBA‐9 suppressed IL‐8 production (p < 0.01). The addition of IM also abolished the induction of TLR2 by P. gingivalis or PgLPS in OBA‐9 and primary cultured HGEC (p < 0.01). The suppressive effect of IM on the induction of TLR2 was also confirmed by immunohistostaining. Stimulation with peptidoglycan, a specific ligand for TLR2, suppressed the expression of toll‐like receptor 4 (TLR4) mRNA in the presence of IM (p < 0.01). However, LPS derived from Escherichia coli, a ligand for TLR4, did not induce the expression of TLR2 mRNA. The PgLPS‐induced expression of TLR4 mRNA was abolished by IM. Knockdown of TLR2 by siRNA transfection resulted in a weaker response of induction of IL8 mRNA in P. gingivalis or PgLPS‐stimulated OBA‐9.

Conclusion

These results suggest that IM suppresses the induction of IL‐8 production by regulating increased levels of TLR2.
Ligature‐induced peri‐implantitis in mice
Authors: Pirih F. Q. , Hiyari S. , Barroso A. D. V. , Jorge A. C. A. , Perussolo J. , Atti E. , Tetradis S. , Camargo P. M.
Published: September 2014

Background and Objective

Peri‐implantitis has a prevalence of 11–47%, involves destruction of peri‐implant bone and may lead to implant loss. A detailed understanding of the pathogenesis of peri‐implantitis is lacking. The objective of this study was to develop a murine model of experimental peri‐implantitis.

Material and Methods

Machined, smooth‐surface, screw‐shaped titanium implants were placed in the healed alveolar bone of the left maxillary molars of C57BL/6J male mice, 8 wk after tooth extraction. Peri‐implantitis was induced by securing silk ligatures around the head of the implant fixtures. Implant survival and peri‐implant bone levels were analyzed by micro‐computed tomography (micro‐CT) scans and histology, 12 wk after ligature placement.

Results

Implant survival was 60% (six of 10) for implants with ligatures and 100% (eight of eight) for controls. Micro‐CT revealed significantly greater bone loss around the implants that received ligatures and that survived, compared with controls. The radiographic findings were confirmed via histology and toluidine blue staining.

Conclusion

This study describes a murine model of experimental peri‐implantitis around screw‐shaped titanium implants placed in the edentulous alveolar bone. This model should be a useful tool to dissect pathogenic mechanisms of peri‐implantitis and evaluate potential treatment interventions.
Spontaneous sleep–wake cycle and sleep deprivation differently induce Bdnf1, Bdnf4 and Bdnf9a DNA methylation and transcripts levels in the basal forebrain and frontal cortex in rats
Authors: Ventskovska Olena , Porkka‐Heiskanen Tarja , Karpova Nina N.
Published: September 2014

Brain‐derived neurotrophic factor (Bdnf) regulates neuronal plasticity, slow wave activity and sleep homeostasis. Environmental stimuli control Bdnf expression through epigenetic mechanisms, but there are no data on epigenetic regulation of Bdnf by sleep or sleep deprivation. Here we investigated whether 5‐methylcytosine (5mC) DNA modification at Bdnf promoters p1, p4 and p9 influences Bdnf1, Bdnf4 and Bdnf9a expression during the normal inactive phase or after sleep deprivation (SD) (3, 6 and 12 h, end‐times being ZT3, ZT6 and ZT12) in rats in two brain areas involved in sleep regulation, the basal forebrain and cortex. We found a daytime variation in cortical Bdnf expression: Bdnf1 expression was highest at ZT6 and Bdnf4 lowest at ZT12. Such variation was not observed in the basal forebrain. Also Bdnf p1 and p9 methylation levels differed only in the cortex, while Bdnf p4 methylation did not vary in either area. Factorial analysis revealed that sleep deprivation significantly induced Bdnf1 and Bdnf4 with the similar pattern for Bdnf9a in both basal forebrain and cortex; 12 h of sleep deprivation decreased 5mC levels at the cortical Bdnf p4 and p9. Regression analysis between the 5mC promoter levels and the corresponding Bdnf transcript expression revealed significant negative correlations for the basal forebrain Bdnf1 and cortical Bdnf9a transcripts in only non‐deprived rats, while these correlations were lost after sleep deprivation. Our results suggest that Bdnf transcription during the light phase of undisturbed sleep–wake cycle but not after SD is regulated at least partially by brain site‐specific DNA methylation.
Exploring the infant feeding practices of immigrant women in the North West of England: a case study of asylum seekers and refugees in Liverpool and Manchester
Authors: Hufton Emily , Raven Joanna
Published: September 2014

Little is known about the infant feeding experiences of refugees residing in the UK. To enable successful health promotion for this population, such experiences must be understood. The study aimed to gain an understanding of infant feeding practices among a group of UK‐based refugee mothers. Objectives were to explore mothers' perceptions and influences of infant feeding practices, to explore challenges faced by mothers in feeding their infants and to identify concerns and experiences of health care professionals with regard to caring for them. Fifteen semi‐structured interviews and two focus group discussions with refugee mothers and five semi‐structured interviews with health care providers were conducted in 2012. A framework approach was used to identify main themes. Overall mothers were dissatisfied with their infant feeding outcomes. A preference to exclusively breastfeed was often not achieved. Most resorted to using formula feed, perceiving that this was primarily due to a lack of support. Mothers who were positive to human immunodeficiency virus followed the UK guidelines of exclusively formula feeding for 6 months, but struggled with guilt of not being able to breastfeed. All mothers unable to exclusively breastfeed experienced a sense of loss. Lack of wider support services coupled with complex lifestyles appeared to create challenges in providing infant feeding support. The results highlight a need for an intensified response to facilitate these mothers to maintain their preferred infant feeding choices, or when required, to support them in the adoption of a new method. Using experienced refugee mothers to guide newer mothers, and integrating health and social care, would be positive starting points.
Weight‐related self‐efficacy in relation to maternal body weight from early pregnancy to 2 years post‐partum
Authors: Lipsky Leah M. , Strawderman Myla S. , Olson Christine M.
Published: September 2014

Excessive gestational weight gain may lead to long‐term increases in maternal body weight and associated health risks. The purpose of this study was to examine the relationship between maternal body weight and weight‐related self‐efficacy from early pregnancy to 2 years post‐partum. Women with live, singleton term infants from a population‐based cohort study were included (n = 595). Healthy eating self‐efficacy and weight control self‐efficacy were assessed prenatally and at 1 year and 2 years post‐partum. Body weight was measured at early pregnancy, before delivery, and 6 weeks, 1 year and 2 years post‐partum. Behavioural (smoking, breastfeeding) and sociodemographic (age, education, marital status, income) covariates were assessed by medical record review and baseline questionnaires. Multi‐level linear regression models were used to examine the longitudinal associations of self‐efficacy measures with body weight. Approximately half of the sample (57%) returned to early pregnancy weight at some point by 2 years post‐partum, and 9% became overweight or obese at 2 years post‐partum. Body weight over time was inversely related to healthy eating (β = −0.57,P = 0.02) and weight control (β = −0.99,P < 0.001) self‐efficacy in the model controlling for both self‐efficacy measures as well as time and behavioural and sociodemographic covariates. Weight‐related self‐efficacy may be an important target for interventions to reduce excessive gestational weight gain and post‐partum weight gain.
Tending a complex microbiota requires major immune complexity
Authors: Stagaman Keaton , Guillemin Karen , Milligan‐Myhre Kathryn
Published: September 2014

Animals maintain complex microbial communities within their guts that fill important roles in the health and development of the host. To what degree a host's genetic background influences the establishment and maintenance of its gut microbial communities is still an open question. We know from studies in mice and humans that external factors, such as diet and environmental sources of microbes, and host immune factors play an important role in shaping the microbial communities (Costello et al. ). In this issue of Molecular Ecology, Bolnick et al. (2014a) sample the gut microbial community from 150 genetically diverse stickleback isolated from a single lake to provide evidence that another part of the adaptive immune response, the major histocompatibility complex class II (MHCII) receptors of antigen‐presenting cells, may play a role in shaping the gut microbiota of the threespine stickleback, Gasterosteus aculeatus (Bolnick et al. 2014a). Bolnick et al. (2014a) provide insight into natural, interindividual variation in the diversity of both stickleback MHCII alleles and their gut microbial communities and correlate changes in the diversity of MHCII receptor alleles with changes in the microbiota.
Testing a ‘genes‐to‐ecosystems’ approach to understanding aquatic–terrestrial linkages
Authors: Crutsinger Gregory M. , Rudman Seth M. , Rodriguez‐Cabal Mariano A. , McKown Athena D. , Sato Takuya , MacDonald Andrew M. , Heavyside Julian , Geraldes Armando , Hart Edmund M. , LeRoy Carri J. , El‐Sabaawi Rana W.
Published: September 2014

A ‘genes‐to‐ecosystems’ approach has been proposed as a novel avenue for integrating the consequences of intraspecific genetic variation with the underlying genetic architecture of a species to shed light on the relationships among hierarchies of ecological organization (genes → individuals → communities → ecosystems). However, attempts to identify genes with major effect on the structure of communities and/or ecosystem processes have been limited and a comprehensive test of this approach has yet to emerge. Here, we present an interdisciplinary field study that integrated a common garden containing different genotypes of a dominant, riparian tree, Populus trichocarpa, and aquatic mesocosms to determine how intraspecific variation in leaf litter alters both terrestrial and aquatic communities and ecosystem functioning. Moreover, we incorporate data from extensive trait screening and genome‐wide association studies estimating the heritability and genes associated with litter characteristics. We found that tree genotypes varied considerably in the quality and production of leaf litter, which contributed to variation in phytoplankton abundances, as well as nutrient dynamics and light availability in aquatic mesocosms. These ‘after‐life’ effects of litter from different genotypes were comparable to the responses of terrestrial communities associated with the living foliage. We found that multiple litter traits corresponding with aquatic community and ecosystem responses differed in their heritability. Moreover, the underlying genetic architecture of these traits was complex, and many genes contributed only a small proportion to phenotypic variation. Our results provide further evidence that genetic variation is a key component of aquatic–terrestrial linkages, but challenge the ability to predict community or ecosystem responses based on the actions of one or a few genes.
Oil shocks and oil producers' growth: where did all the spending go?
Authors: El Anshasy Amany A.
Published: September 2014

I use panel unit root tests and panel error correction models to examine the effects of oil windfall shocks and types of public spending on economic performance in 16 oil‐producing countries over the period 1972–2008. Higher oil prices seem toreducenon‐oil growth in the long run, butstimulateit in the short run. However, oil abundance may or may not become a ‘curse’ conditional on how the windfalls are managed. I find that the large windfalls of the 1970s and the 2000s have contributed to the slow long‐run growth performance, after controlling for the composition of public spending. Public sector wages stimulated long‐run non‐oil growth in more oil‐abundant economies; but had a negative effect in less oil‐endowed countries. The large public investment programs were not effective in stimulating non‐oil long‐run growth; and the higher the dependency on oil, the lesser the contribution of new infrastructure investments to the non‐oil sector's growth.
Pediatric airway anatomy may not be what we thought: implications for clinical practice and the use of cuffed endotracheal tubes
Authors: Tobias Joseph D.
Published: September 2014

One of the long held tenets of pediatric anesthesia has been the notion that the pediatric airway is conical shape with the narrowest area being the cricoid region. However, recent studies using radiologic imaging techniques (magnetic resonance imaging and computed tomography) or direct bronchoscopic observation have questioned this suggesting that the narrowest segment may be at or just below the glottic opening. More importantly, it has been clearly demonstrated that the airway is elliptical in shape rather than circular with the anterior–posterior dimension being greater than the transverse dimension. These findings coupled with the development of a new generation of cuffed endotracheal tubes (ETTs) with a thin, polyurethane cuff have caused a transition in the practice of pediatric anesthesiology with an increased use of cuffed ETTs, even in neonates and infants. The following article reviews the historical data leading to the assumption that the pediatric airway is conical as well as the more recent imaging and direct bronchoscopic observational studies which refute this tenet. The transition to the use of cuffed ETTs is discussed and potential advantages presented in both the operating room and the intensive care unit. Issues regarding the monitoring of intracuff pressure and techniques to limit potential morbidity related to a high intracuff pressure are outlined.
Improving Photoprotection Attitudes in the Tropics: Sunburn vs Vitamin D
Authors: Silva Abel A.
Published: September 2014

The ultraviolet radiation of type B (the UVB) stimulates both the production of vitamin D (VD) and the incorporation of erythema dose (ED). The UVA also contributes to ED. The turning point between the benefit of producing VD and the harm of incorporating ED cannot be determined easily. However, the casual behavior regarding the exposure to the Sun can be changed in order to improve the protoprotection attitudes and create a trend towards benefit. In the case, people living in the low latitudes should exposure themselves to the Sun for a determined time interval within the noon time and avoid the Sun in other periods. This would produce an adequate amount of VD through the VD dose (207–214 J m−2) against minimum ED (≈105 J m−2) for skin type II. For it, unprotected forearms and hands must be exposed to the noon Sun (cloudless) for 11 min (winter) and 5 min (summer). The exposure at other times different from noon can represent increases of up to 24% in ED and up to 12 times in the time interval to be in the Sun in relation to the minimum amounts of both ED and time interval at noon.
Skin Responses to Micro Scale Field Size of Solar‐Simulated Radiation – Preliminary Evaluation by Reflectance Confocal Microscopy in vivo
Authors: Seo InSeok , Chu Melissa , Bargo Paulo R. , Kollias Nikiforos
Published: September 2014

Erythema and pigment responses of human skin following an acute exposure to ultraviolet radiation (UVR) are frequently used to determine the photosensitivity of the skin. In this study we investigated the responses of the skin to a micro‐scale area of UVR exposure (MiR) and compared the responses to a macro‐scale area of exposure (MaR). Ten human volunteers were tested with solar‐simulated radiation on their upper arm or back using a beam size of 8 mm and 0.2 mm in diameter. The fluence required to produce a minimally perceptible erythema (MED) using the MiR was found to be higher than that for the MaR. The erythema response extended beyond the exposed area and this became pronounced when the beam size was microscopic. Reflectance confocal microscopy in vivo revealed that MiR induced cellular alterations within a confined area of smaller dimensions than the area of exposure. Pigment responses were confined within the areas of cellular damage. The erythema expression of exposed skin recovered faster for the sites receiving MiR even when the applied fluence was higher than the MED for the MaR. Through the use of MiR we were able to visualize spatially dissimilar skin responses of erythema and pigmentation suggesting different cellular mechanisms.
Sun Exposure and Vitamin D Status as Northeast Asian Migrants Become Acculturated to Life in Australia
Authors: Guo Shuyu , Gies Peter , King Kerryn , Lucas Robyn M
Published: September 2014

Vitamin D deficiency is more common in Northeast‐Asian immigrants to western countries than in the local population; prevalence equalizes as immigrants adopt the host country's culture. In a community‐based study of 100 Northeast‐Asian immigrants in Canberra, Australia, we examined predictors of vitamin D status, its association with indicators of acculturation (English language use; time since migration) and mediators of that association. Participants completed a sun and physical activity diary and wore an electronic ultraviolet radiation (UVR) dosimeter for 7 days. Skin colour was measured by reflectance spectrophotometry. Serum concentrations of 25‐hydroxyvitamin D (25(OH)D) and cardio‐metabolic biomarkers were measured on fasting blood. In a multiple linear regression model, predictors for 25(OH)D concentration were season of blood collection, vitamin D supplementation, UVR exposure, body mass index, physical activity and having private health insurance (R2 = 0.57). Greater acculturation was associated with lower risk of vitamin D deficiency (de‐seasonalized 25(OH)D level <50 nmol L−1) (Adjusted Odds Ratio (AOR): 0.22 [95%CI 0.04–0.96]); this association was statistically mediated by physical activity and time outdoors. Vitamin D deficiency was associated with higher total cholesterol levels (>5.0 mmol L−1) (AOR: 7.48 [95%CI 1.51–37.0]). Targeted public health approaches are required to manage the high prevalence of vitamin D deficiency in migrants retaining a traditional lifestyle.
The Employment of a Removable Chitosan‐Derivatized Polymeric Sensitizer in the Photooxidation of Polyhydroxylated Water‐Pollutants
Authors: Ferrari Gabriela V. , Andrada María E. , Natera José , Muñoz Vanesa A. , Paulina Montaña M. , Gambetta Carolina , Boiero María L. , Montenegro Mariana A. , Massad Walter A. , García Norman A.
Published: September 2014

The known O2(1∆g)‐sensitizer system Chitosan bounded Rose Bengal (CH‐RB), with Rose Bengal (RB) immobilized by irreversible covalent bonding to the polymer Chitosan (CH), soluble in aquous acidic medium, was employed in the photodegradation of three tri‐hydroxy benzene water‐contaminants (THBs). The system sensitizes the O2(1∆g)‐mediated photodegradation of THBs by a process kinetically favored, as compared to that employing free RB dissolved in the same solvent. Additionally the free xanthene dye, degradable by O2(1∆g) through self‐sensitization upon prolonged light‐exposure, is considerably protected when bonded to CH‐polymer. The polymeric sensitizer, totally insoluble in neutral medium, can be removed from the solution after the photodegradative cycle by precipitation through a simple pH change. This fact constitutes an interesting aspect in the context of photoremediation of confined polluted waters. In other words, the sensitizing system could be useful for avoiding to dissolve dyestuffs in the polluted waters, in order to act as conventional sunlight‐absorbing dye‐sensitizers. In parallel the interaction CH ‐ O2(1∆g) in acidic solution was evaluated. The polymer quenches the oxidative species with a rate constant 2.4 × 108 M−1 s−1 being the process mostly attributable to a physical interaction. This fact promotes the photoprotection of the bonded dye in the CH‐RB polymer.
Immune response in susceptible BALB/c mice immunized with DNA encoding Lipophosphoglycan 3 of Leishmania infantum
Authors: Pirdel L. , Zavaran Hosseini A. , Rasouli M.
Published: September 2014

Visceral leishmaniasis is a serious parasitic infection that the development of an effective vaccine is necessary to control the disease. Lipophosphoglycan 3 (LPG3) is essential for the synthesis of glycoconjugates as parasite virulence factors. In this study, we evaluated the immunogenicity of Leishmania infantum LPG3 gene as a DNA vaccine against murine visceral leishmaniasis. For this purpose, BALB/c mice were immunized subcutaneously with the DNA encoding LPG3 either alone or in combination with recombinant heat shock protein 70 (rHSP70). Next, its immunogenicity and protective efficacy were evaluated in the immunized mice. The results showed a mixed Th1/Th2 response following immunization, which was associated with the production of both IFN‐γ and IL‐10 by splenocytes compared with control groups but did not lead to reduction in the splenic parasite burden. Serum levels of IgG antibody isotypes indicated no significant difference between the LPG3 DNA and the empty vector. In addition, the co‐administration of rHSP70 with the DNA vaccine offered no additive protective advantage on experimental infectious challenge. Thus, we propose to strengthen the immunogenic potential of L. infantum LPG3 in prime‐boost approach with a powerful adjuvant to elicit a robust parasite‐specific protective Th1 response.
Variation in plant‐mediated interactions between rhizobacteria and caterpillars: potential role of soil composition
Authors: Pangesti N. , Pineda A. , Dicke M. , van Loon J. J. A.
Published: September 2014

Selected strains of non‐pathogenic rhizobacteria can trigger induced systemic resistance (ISR) in plants against aboveground insect herbivores. However, the underlying mechanisms of plant‐mediated interactions between rhizobacteria and herbivorous insects are still poorly understood. UsingArabidopsis thalianaCol‐0–Pseudomonas fluorescensWCS417r as a model system, we investigated the performance and the molecular mechanisms underlying plant‐mediated effects of rhizobacteria on the generalist caterpillarMamestra brassicaeand the specialistPieris brassicae. Rhizobacteria colonisation ofArabidopsisroots resulted in decreased larval weight ofM. brassicae,whereas no effect was observed on larval weight ofP. brassicae. Using a jasmonic acid (JA)‐impaired mutant (dde2‐2), we confirmed the importance ofJAin rhizobacteria‐mediatedISRagainstM. brassicae. Interestingly, in some experiments we also observed rhizobacteria‐induced systemic susceptibility toM. brassicae. The role of soil composition in the variable outcomes of microbe–plant–insect interactions was then assessed by comparingM. brassicaeperformance and gene transcription in plants grown in potting soil or a mixture of potting soil and sand in a 1:1 ratio. In a mixture of potting soil and sand, rhizobacteria treatment had a consistent negative effect onM. brassicae, whereas the effect was more variable in potting soil. Interestingly, at 24 h post‐infestation (hpi) rhizobacteria treatment primed plants grown in a mixture of potting soil and sand for stronger expression of theJA‐ and ethylene‐regulated genesPDF1.2andHEL, respectively. Our study shows that soil composition can modulate rhizobacteria–plant–insect interactions, and is a factor that should be considered when studying these belowground–aboveground interactions.
Evaluation of Malaysian oil palm progenies for susceptibility, resistance or tolerance to Fusarium oxysporum f. sp. elaeidis and defence‐related gene expression in roots
Authors: Rusli M. H. , Idris A. S. , Cooper R. M.
Published: September 2014

Vascular wilt of oil palm caused by Fusarium oxysporum f. sp. elaeidis (Foe) is a devastating disease in West and Central Africa. As the oil palm industry in southeast Asia is still expanding, so is the oil palm germplasm collection through the importation of seed and pollen from Africa, the centre of diversity for Elaeis guineensis. There is a risk of inadvertent spread of the disease on contaminated seed or pollen. Regular re‐evaluation of the reaction of currently grown palm genotypes towards Foe is clearly required for biosecurity. This study has demonstrated that four Malaysian oil palm progenies, three in current or recent commercial use, are highly susceptible to infection by at least one of two African isolates of Foe, representing different countries, aggressiveness and vegetative compatibility groups. Symptoms and reduction of palm growth generally reflected the extent and intensity of systemic colonization by Foe. Progeny PK 5463 expressed partial resistance to Foe isolate F3, but not to isolate 16F, displaying significantly milder symptoms and supporting less widespread vascular colonization. This relatively incompatible interaction was used to study expression of potential defence‐related genes during root infection when compared to a susceptible palm–isolate combination. The only significant response was an early up‐regulation of chitinase in resistant palms. The research revealed at least one progeny–isolate differential interaction, and the associated resistance expression suggests a component of tolerance, because colonization by Foe was systemic in both compatible and incompatible combinations.
Rational and Compassionate Information Processing: A Conceptual Framework for Authentic Dialogue
Authors: Choi Taehyon
Published: September 2014

Authentic dialogue is a key component of deliberative democracy. Public administration scholars and practitioners have focused on institutional settings for authentic dialogue, but they have paid less attention to behavioral aspects, especially the emotional component, of authentic dialogue. The author proposes a conceptual framework for authentic dialogue that highlights the three dimensions of its social‐behavioral foundation: epistemic, social, and compassionate information processing motivation. The article reviews the discourse on authentic dialogue in public administration and provides a conceptual framework for authentic dialogue, with a discussion of the three behavioral dimensions, their relationships, and their effects. This framework may be used in empirical analysis of authentic dialogue and the design of institutions for deliberative democracy.
The Multiscale Importance of Road Segments in a Network Disruption Scenario: A Risk‐Based Approach
Authors: Freiria Susana , Tavares Alexandre O. , Pedro Julião Rui
Published: September 2014

This article addresses the problem of the multiscale importance of road networks, with the aim of helping to establish a more resilient network in the event of a road disruption scenario. A new model for identifying the most important roads is described and applied on a local and regional scale. The work presented here represents a step forward, since it focuses on the interaction between identifying the most important roads in a network that connect people and health services, the specificity of the natural hazards that threaten the normal functioning of the network, and an assessment of the consequences of three real‐world interruptions from a multiscale perspective. The case studies concern three different past events: road interruptions due to a flood, a forest fire, and a mass movement. On the basis of the results obtained, it is possible to establish the roads for which risk management should be a priority. The multiscale perspective shows that in a road interruption the regional system may have the capacity to reorganize itself, although the interruption may have consequences for local dynamics. Coordination between local and regional scales is therefore important. The model proposed here allows for the scaling of emergency response facilities and human and physical resources. It represents an innovative approach to defining priorities, not only in the prevention phase but also in terms of the response to natural disasters, such as awareness of the consequences of road disruption for the rescue services sent out to local communities.
THORACOLUMBAR INTRADURAL DISC HERNIATION IN EIGHT DOGS: CLINICAL, LOW‐FIELD MAGNETIC RESONANCE IMAGING, AND COMPUTED TOMOGRAPHIC MYELOGRAPHY FINDINGS
Authors: Tamura Shinji , Doi Shoko , Tamura Yumiko , Takahashi Kuniaki , Enomoto Hirokazu , Ozawa Tsuyoshi , Uchida Kazuyuki
Published: September 2014

Intradural disc herniation is a rarely reported cause of neurologic deficits in dogs and few published studies have described comparative imaging characteristics. The purpose of this retrospective cross sectional study was to describe clinical and imaging findings in a group of dogs with confirmed thoracolumbar intradural disc herniation. Included dogs were referred to one of four clinics, had acute mono/paraparesis or paraplegia, had low field magnetic resonance imaging (MRI) and/or computed tomographic myelography, and were diagnosed with thoracolumbar intradural disc herniation during surgery. Eight dogs met inclusion criteria. The prevalence of thoracolumbar intradural disc herniation amongst the total population of dogs that developed a thoracolumbar intervertebral disc herniation and that were treated with a surgical procedure was 0.5%. Five dogs were examined using low‐field MRI. Lesions that were suspected to be intervertebral disc herniations were observed; however, there were no specific findings indicating that the nucleus pulposus had penetrated into the subarachnoid space or into the spinal cord parenchyma. Thus, the dogs were misdiagnosed as having a conventional intervertebral disc herniation. An intradural extramedullary disc herniation (three cases) or intramedullary disc herniation (two cases) was confirmed during surgery. By using computed tomographic myelography (CTM) for the remaining three dogs, an intradural extramedullary mass surrounded by an accumulation of contrast medium was observed and confirmed during surgery. Findings from this small sample of eight dogs indicated that CTM may be more sensitive for diagnosing canine thoracolumbar intradural disc herniation than low‐field MRI.
Composition of the stubble weed flora and its role for Heterodera schachtii in the year preceding sugar beet production
Authors: Meinecke A , Ziegler K , Bürcky K , Westphal A
Published: September 2014

In Germany, sugar beet is often rotated with 2 years of cereal. Extensive fallow periods between cereal harvest and autumn primary tillage allow for a weed flora to develop. Broad‐leaved weeds could potentially be alternate hosts for the common nematode Heterodera schachtii, one of the most important pests of sugar beet. Between 2009 and 2012, annual weeds developing in cereal stubble fields during July to mid‐October in the season prior to sugar beet were surveyed, including known hosts of H. schachtii. Yearly weather patterns and agronomic practices possibly impacted weed species composition and weed population densities. During September, Chenopodium album, Cirsium arvense, Convolvulus arvensis, Mercurialis annua, Polygonum spp., Solanum nigrum and Sonchus spp. occurred at the highest frequencies. Weed hosts of H. schachtii were present, but densities, frequencies and uniformity were limited. In 2010 and 2011, staining for nematodes in roots revealed juvenile penetration of some weeds but few adult stages. No indication of nematode reproduction of H. schachtii was found on these weed hosts. A fairly stable weed flora was detected on stubble fields that could provide some carry over for weed species. An elevated risk for nematode population density build‐up on these weeds was not found and management of these weeds at the observed densities during the stubble period for nematological reasons appeared unnecessary.
Rac1 – a novel regulator of contraction‐stimulated glucose uptake in skeletal muscle
Authors: Sylow Lykke , Møller Lisbeth L. V. , Kleinert Maximilian , Richter Erik A. , Jensen Thomas E.
Published: September 2014

New Findings

What is the topic of this review?

Novel evidence indicates a role of the GTPase Rac1 in the regulation of exercise‐ and contraction‐stimulated glucose uptake in skeletal muscle.

What advances does it highlight?

The intracellular mechanisms regulating exercise and contraction‐stimulated glucose uptake in muscle are not well understood. Recent findings from our group suggest that Rac1 is an important regulator of contraction‐stimulated glucose uptake. In this review, we discuss published and unpublished findings supporting a role of Rac1 in exercise/contraction‐stimulated glucose uptake. The possible downstream effectors of Rac1 are also considered.

Muscle contraction stimulates muscle glucose uptake by facilitating translocation of glucose transporter 4 from intracellular locations to the cell surface, which allows for diffusion of glucose into the myofibres. The intracellular mechanisms regulating this process are not well understood. The GTPase Rac1 has, until recently, been investigated only with regard to its involvement in insulin‐stimulated glucose uptake. However, we recently found that Rac1 is activated during muscle contraction and exercise in mice and humans. Remarkably, Rac1 seems to be necessary for exercise and contraction‐stimulated glucose uptake in skeletal muscle, because muscle‐specific Rac1 knockout mice display reduced ex vivo contraction‐ and in vivo exercise‐stimulated glucose uptake. The molecular mechanism by which Rac1 regulates glucose uptake is presently unknown. However, recent studies link Rac1 to the actin cytoskeleton, the small GTPase RalA and/or free radical production, which have previously been shown to be regulators of glucose uptake in muscle. We propose a model in which Rac1 is activated by contraction‐ and exercise‐induced mechanical stress signals and that Rac1 in conjunction with other signalling regulates glucose uptake during muscle contraction and exercise.
Retour aux sources: defining the structural basis of glutamate receptor activation
Authors: Dawe G. Brent , Aurousseau Mark R. , Daniels Bryan A. , Bowie Derek
Published: September 2014

Ionotropic glutamate receptors (iGluRs) are the major excitatory neurotransmitter receptor in the vertebrate CNS and, as a result, their activation properties lie at the heart of much of the neuronal network activity observed in the developing and adult brain. iGluRs have also been implicated in many nervous system disorders associated with postnatal development (e.g. autism, schizophrenia), cerebral insult (e.g. stroke, epilepsy), and disorders of the ageing brain (e.g. Alzheimer's disease, Parkinsonism). In view of this, an emphasis has been placed on understanding how iGluRs activate and desensitize in functional and structural terms. Early structural models of iGluRs suggested that the strength of the agonist response was primarily governed by the degree of closure induced in the ligand‐binding domain (LBD). However, recent studies have suggested a more nuanced role for the LBD with current evidence identifying the iGluR LBD interface as a “hotspot” regulating agonist behaviour. Such ideas remain to be consolidated with recently solved structures of full‐length iGluRs to account for the global changes that underlie channel activation and desensitization.
The properties, distribution and function of Na+–Ca2+ exchanger isoforms in rat cutaneous sensory neurons
Authors: Scheff N. N. , Yilmaz E. , Gold M. S.
Published: September 2014

Key points

There has been little if any systematic analysis of the Na+–Ca2+ exchanger (NCX) in sensory neurons despite conflicting results in the literature regarding the extent to which it contributes to the regulation of intracellular Ca2+ in these neurons.

While the differential distribution and/or biophysical properties of NCX isoforms may contribute to these conflicting results, only indirect evidence points to the consequences of NCX activity on afferent function.

NCX activity is restricted to a subpopulation of putative nociceptive neurons.

All three NCX isoforms are expressed in putative nociceptive afferents and appear to be differentially distributed along major neuron compartments: central axon, cell body and peripheral axon.

NCX 3 plays a dominant role in the regulation of the duration of the evoked Ca2+ transient in the cell body, regulation of the action potential conduction velocity, and establishment of nociceptive threshold.

The Na+–Ca2+ exchanger (NCX) appears to play an important role in the regulation of the high K+‐evoked Ca2+ transient in putative nociceptive dorsal root ganglion (DRG) neurons. The purpose of the present study was to (1) characterize the properties of NCX activity in subpopulations of DRG neurons, (2) identify the isoform(s) underlying NCX activity, and (3) begin to assess the function of the isoform(s) in vivo. In retrogradely labelled neurons from the glabrous skin of adult male Sprague–Dawley rats, NCX activity, as assessed with fura‐2‐based microfluorimetry, was only detected in putative nociceptive IB4+ neurons. There were two modes of NCX activity: one was evoked in response to relatively large and long lasting (∼325 nm for >12 s) increases in the concentration of intracellular Ca2+ ([Ca2+]i), and a second was active at resting [Ca2+]i > ∼150 nm. There also were two modes of evoked activity: one that decayed relatively rapidly (<5 min) and a second that persisted (>10 min). Whereas mRNA encoding all three NCX isoforms (NCX1–3) was detected in putative nociceptive cutaneous neurons with single cell PCR, pharmacological analysis and small interfering RNA (siRNA) knockdown of each isoform in vivo suggested that NCX2 and 3 were responsible for NCX activity. Western blot analyses suggested that NCX isoforms were differentially distributed within sensory neurons. Functional assays of excitability, action potential propagation, and nociceptive behaviour suggest NCX activity has little influence on excitability per se, but instead influences axonal conduction velocity, resting membrane potential, and nociceptive threshold. Together these results indicate that the function of NCX in the regulation of [Ca2+]i in putative nociceptive neurons may be unique relative to other cells in which these exchanger isoforms have been characterized and it has the potential to influence sensory neuron properties at multiple levels.
k‐space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR‐based PET attenuation correction
Authors: Hu Lingzhi , Su Kuan‐Hao , Pereira Gisele C. , Grover Anu , Traughber Bryan , Traughber Melanie , Muzic Raymond F.
Published: September 2014

Purpose:

The ultrashort echo‐time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k‐space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone‐enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR.

Methods:

An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2∗ = 1/T2∗, was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone‐enhanced image quality, image noise, water fraction, and R2∗ of cortical bone.

Results:

A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2∗ of human skull was measured as 0.2–0.3 ms−1 depending on the specific region, which is more than ten times greater than the R2∗ of soft tissue. The water fraction in human skull was measured to be 60%–80%, which is significantly less than the >90% water fraction in brain. High‐quality, bone‐enhanced images can be generated using a reduced sampled UTE sequence with no visible compromise in image quality and they preserved bone‐to‐air contrast with as low as a 25% sampling rate.

Conclusions:

This UTE strategy with angular undersampling preserves the image quality and contrast of cortical bone, while reducing the total scanning time by as much as 75%. The quantitative results of R2∗ and the water fraction of skull based on Dixon analysis of UTE images acquired at multiple echo times provide guidance for the clinical adoption and further parameter optimization of the UTE sequence when used for radiation therapy and MR‐based PET attenuation correction.
Speech intelligibility estimation using multi-resolution spectral features for speakers undergoing cancer treatment
Authors: Kim Jonathan C. , Rao Hrishikesh , Clements Mark A.
Published: September 2014

Head and neck cancer can significantly hamper speech production which often reduces speech intelligibility. A method of extracting spectral features is presented. The method uses a multi-resolution sinusoidal transform scheme, which enables better representation of spectral and harmonic characteristics. Regression methods were used to predict interval-scaled intelligibility scores of utterances in the NKI-CCRT speech corpus. The inclusion of these features lowered the mean squared estimation error from 0.43 to 0.39 on a scale from 1 to 7, with a p-value less than 0.001. For binary intelligibility classification, their inclusion resulted in an improvement by 5.0 percentage points when tested on a disjoint set.
Cloning and Characterization of a Novel Esterase from Rhodococcus sp. for Highly Enantioselective Synthesis of a Chiral Cilastatin Precursor
Authors: Zhang Yan , Pan Jiang , Luan Zheng-Jiao , Xu Guo-Chao , Park Sunghoon , Xu Jian-He
Published: September 2014

A novel nonheme chloroperoxidase (
Rh
Est1), with promiscuous esterase activity for enantioselective hydrolysis of ethyl (
S
)-2,2-dimethylcyclopropanecarboxylate, was identified from a shotgun library of
Rhodococcus
sp. strain ECU1013.
Rh
Est1 was overexpressed in
Escherichia coli
BL21(DE3), purified to homogeneity, and functionally characterized. Fingerprinting analysis revealed that
Rh
Est1 prefers
para
-nitrophenyl (
p
NP) esters of short-chain acyl groups.
p
NP esters with a cyclic acyl moiety, especially that with a cyclobutanyl group, were also substrates for
Rh
Est1. The

K
m

values for methyl 2,2-dimethylcyclopropanecarboxylate (DmCpCm) and ethyl 2,2-dimethylcyclopropane carboxylate (DmCpCe) were 0.25 and 0.43 mM, respectively.
Rh
Est1 could serve as an efficient hydrolase for the bioproduction of optically pure (
S
)-2,2-dimethyl cyclopropane carboxylic acid (DmCpCa), which is an important chiral building block for cilastatin. As much as 0.5 M DmCpCe was enantioselectively hydrolyzed into (
S
)-DmCpCa, with a molar yield of 47.8% and an enantiomeric excess (
ee
) of 97.5%, indicating an extremely high enantioselectivity (
E
= 240) of this novel and unique biocatalyst for green manufacturing of highly valuable chiral chemicals.
Time-Scaled Evolutionary Analysis of the Transmission and Antibiotic Resistance Dynamics of Staphylococcus aureus Clonal Complex 398
Authors: Ward M. J. , Gibbons C. L. , McAdam P. R. , van Bunnik B. A. D. , Girvan E. K. , Edwards G. F. , Fitzgerald J. R. , Woolhouse M. E. J.
Published: September 2014

Staphylococcus aureus
clonal complex 398 (CC398) is associated with disease in humans and livestock, and its origins and transmission have generated considerable interest. We performed a time-scaled phylogenetic analysis of CC398, including sequenced isolates from the United Kingdom (Scotland), along with publicly available genomes. Using state-of-the-art methods for mapping traits onto phylogenies, we quantified transitions between host species to identify sink and source populations for CC398 and employed a novel approach to investigate the gain and loss of antibiotic resistance in CC398 over time. We identified distinct human- and livestock-associated CC398 clades and observed multiple transmissions of CC398 from livestock to humans and between countries, lending quantitative support to previous reports. Of note, we identified a subclade within the livestock-associated clade comprised of isolates from hospital environments and newborn babies, suggesting that livestock-associated CC398 is capable of onward transmission in hospitals. In addition, our analysis revealed significant differences in the dynamics of resistance to methicillin and tetracycline related to contrasting historical patterns of antibiotic usage between the livestock industry and human medicine. We also identified significant differences in patterns of gain and loss of different tetracycline resistance determinants, which we ascribe to epistatic interactions between the resistance genes and/or differences in the modes of inheritance of the resistance determinants.