bluuebunny/crossref_metadata_2025 huggingface dataset:
Type 2 diabetes mellitus is associated with altered CD8+ T and natural killer cell function in pulmonary tuberculosis
Authors: Kumar Nathella P. , Sridhar Rathinam , Nair Dina , Banurekha Vaithilingam V. , Nutman Thomas B. , Babu Subash
Published: November 2014

Type 2 diabetes mellitus (DM) is associated with expanded frequencies of mycobacterial antigen‐specific CD4+ T helper type 1 (Th1) and Th17 cells in individuals with active pulmonary tuberculosis (TB). No data are available on the role of CD8+ T and natural killer (NK) cells in TB with coincident DM. To identify the role of CD8+ T and NK cells in pulmonary TB with diabetes, we examined mycobacteria‐specific immune responses in the whole blood of individuals with TB and DM (TB‐DM) and compared them with those without DM (TB‐NDM). We found that TB‐DM is characterized by elevated frequencies of mycobacterial antigen‐stimulated CD8+ T cells expressing type 1 [interferon‐γ and interleukin‐2 (IL‐2)] and type 17 (IL‐17F) cytokines. We also found that TB‐DM is characterized by expanded frequencies of TB antigen‐stimulated NK cells expressing type 1 (tumour necrosis factor‐α) and type 17 (IL‐17A and IL‐17F) cytokines. In contrast, CD8+ T cells were associated with significantly diminished expression of the cytotoxic markers perforin, granzyme B and CD107a both at baseline and following antigen or anti‐CD3 stimulation, while NK cells were associated with significantly decreased antigen‐stimulated expression of CD107a only. This was not associated with alterations in CD8+ T‐cell or NK cell numbers or subset distribution. Therefore, our data suggest that pulmonary TB complicated with type 2 DM is associated with an altered repertoire of cytokine‐producing and cytotoxic molecule‐expressing CD8+ T and NK cells, possibly contributing to increased pathology.
A novel highly pathogenic H5N8 avian influenza virus isolated from a wild duck in China
Authors: Fan Shengtao , Zhou Lichen , Wu Di , Gao Xiaolong , Pei Enle , Wang Tianhou , Gao Yuwei , Xia Xianzhu
Published: November 2014

Migrating wild birds are considered natural reservoirs of influenza viruses and serve as a potential source of novel influenza strains in humans and livestock. During routine avian influenza surveillance conducted in eastern China, a novel H5N8 (SH‐9) reassortant influenza virus was isolated from a mallard duck in China. blast analysis revealed that the HA, NA, PB1, PA, NP, and M segments of SH‐9 were most closely related to the corresponding segments of A/duck/Jiangsu/k1203/2010 (H5N8). The SH‐9 virus preferentially recognized avian‐like influenza virus receptors and was highly pathogenic in mice. Our results suggest that wild birds could acquire the H5N8 virus from breeding ducks and spread the virus via migratory bird flyways.
Distributional dynamics and interspecific gene flow in Picea likiangensis and P. wilsonii triggered by climate change on the Qinghai‐Tibet Plateau
Authors: Sun Yongshuai , Li Lili , Li Long , Zou Jiabin , Liu Jianquan
Published: November 2014

Aim

To address whether climate changes have altered the distributional ranges of cold‐preferring conifer species, and whether this has influenced interspecific divergence.

Location

Qinghai‐Tibet Plateau (QTP), Asia.

Methods

We obtained DNA sequences at 13 nuclear loci in 229 individuals collected from 32 populations across the range of two cold‐preferring alpine species, Picea likiangensis and Picea wilsonii. Bayesian skyline plots (BSPs) were used to examine historical changes in effective population sizes. Species distributions were reconstructed based on presence‐only data at 134 locations and climate variables from the WorldClim database, and the reconstructed distributions were compared with projected palaeodistributions at the Last Glacial Maximum (LGM, about 20 ka). Four models of interspecific gene flow during the Pleistocene and Holocene were compared using approximate Bayesian computation (ABC).

Results

The effective population sizes of P. likiangensis and P. wilsonii increased continuously from 5 to 0.2 Ma, but decreased after 0.2 Ma. The distributional ranges during the LGM were wider than at present, confirming the trend of a recent decrease. However, the overlapping area became greater due to their shifted distributions, and these shifts altered the major direction of continuing interspecific gene flow.

Main conclusions

The early increase in the distributions of these two species might have been triggered by enlargements of the available cold habitats brought about by QTP uplift and Pleistocene glaciations. However, the distributional ranges decreased in response to climatic warming since the end of the largest glaciation. These distributional changes further retarded the process of differentiation by altering the pattern of gene flow. Our results shed light on the evolutionary complexity of alpine species in response to climate changes in this climate‐sensitive biodiversity hotspot.
The effect of intermittent use of occlusal splint devices on sleep bruxism: a 4‐week observation with a portable electromyographic recording device
Authors: Matsumoto H. , Tsukiyama Y. , Kuwatsuru R. , Koyano K.
Published: November 2014

This randomised controlled study investigated the effect of intermittent use of occlusal splints on sleep bruxism compared with that of continuous use by measuring masseter muscle electromyographic activity using a portable electromyographic recording system. Twenty bruxers were randomly allocated to the continuous group and intermittent group. Subjects in the continuous group wore stabilisation splints during sleep for 29 nights continuously, whereas those in the intermittent group wore splints during sleep every other week, that is they used splints on the 1st–7th, 15th–21st and 29th nights. Electromyographic activity of the masseter muscle during sleep was recorded for the following six time points: before (baseline), immediately after, and 1, 2, 3 and 4 weeks after the insertion of a stabilisation splint. The number of nocturnal masseter electromyographic events, duration and the total activity of sleep bruxism were analysed. In the continuous group, nocturnal masseter electromyographic events were significantly reduced immediately and 1 week after the insertion of the stabilisation splint, and duration was reduced immediately after the insertion (P < 0·05, Dunnett's test), but no reduction was observed at 2, 3 and 4 weeks after insertion. In the intermittent group, nocturnal masseter electromyographic events and duration were significantly reduced immediately after and also 4 weeks after insertion of the stabilisation splint (P < 0·05, Dunnett's test). The obtained results of the present exploratory trial indicate that the intermittent use of stabilisation splints may reduce sleep bruxism activity for a longer period compared with that of continuous use.
Diel variation of the cellular carbon to nitrogen ratio of Chlorella autotrophica (Chlorophyta) growing in phosphorus‐ and nitrogen‐limited continuous cultures
Authors: Ng Wai Ho Albert , Liu Hongbin
Published: November 2014

We investigated the relationship between daily growth rates and diel variation of carbon (C) metabolism and C to nitrogen (N) ratio under P‐ and N‐limitation in the green algae Chlorella autotrophica. To do this, continuous cultures of C. autotrophica were maintained in a cyclostat culture system under 14:10 light:dark cycle over a series of P‐ and N‐limited growth rates. Cell abundance, together with cell size, as reflected by side scatter signal from flow cytometric analysis demonstrated a synchronized diel pattern with cell division occurring at night. Under either type of nutrient limitation, the cellular C:N ratio increased through the light period and decreased through the dark period over all growth rates, indicating a higher diel variation of C metabolism than that of N. Daily average cellular C:N ratios were higher at lower dilution rates under both types of nutrient limitation but cell enlargement was only observed at lower dilution rates under P‐limitation. Carbon specific growth rates during the dark period positively correlated with cellular daily growth rates (dilution rates), with net loss of C during night at the lowest growth rates under N‐limitation. Under P‐limitation, dark C specific growth rates were close to zero at low dilution rates but also exhibited an increasing trend at high dilution rates. In general, diel variations of cellular C:N were low when dark C specific growth rates were high. This result indicated that the fast growing cells performed dark C assimilation at high rates, hence diminished the uncoupling of C and N metabolism at night.
Relationship of stigma behaviors and breeding system in three Mazus (Phrymaceae) species with bilobed stigma
Authors: Jin Xiao‐Fang , Ye Zhong‐Ming , Wang Qing‐Feng , Yang Chun‐Feng
Published: November 2014

Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self‐spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self‐pollen. Mazus stachydifolius was self‐incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing.
Barriers, rather than refugia, underlie the origin of diversity in toads endemic to the Brazilian Atlantic Forest
Authors: Thomé Maria Tereza C. , Zamudio Kelly R. , Haddad Célio F. B. , Alexandrino João
Published: November 2014

In this study, we investigated the relative contribution of geographic barriers and Pleistocene refuges in the diversification of the Rhinella crucifer species complex, a group of endemic toads with a widespread distribution in the Brazilian Atlantic Forest (AF). We used intensive sampling and multilocus DNA sequence data to compare nucleotide diversity between refuge and nonrefuge areas, investigate regional demographic patterns, estimate demographic parameters related to genetic breaks and test refuge versus barrier scenarios of diversification using approximate Bayesian computation. We did not find higher levels of genetic diversity in putative refuge areas, either at regional or biome scale. Rather, the demographic history of the species complex supports regional differences with moderate population growth in the north and central regions and stability in southern AF. Genetic breaks were dated to the Plio–Pleistocene; however, our analyses rejected the role of refuges in creating a northern and central divergence, supporting a recent colonization scenario at a smaller scale within the central AF. Overall, our data rule out massive climatically driven fragmentation and large‐scale recolonization events for populations across the biome. We confirmed the importance of geographic barriers in creating main divergences and underscored the importance of searching for cryptic discontinuities in the landscape. Comparison of our results with those of other AF taxa indicates organismal specific responses to moderate shifts in habitat and that multiple refuges may constitute a more realistic model for diversification of Atlantic Forest biota.
Riluzole is a radio‐sensitizing agent in an in vivo model of brain metastasis derived from GRM1 expressing human melanoma cells
Authors: Wall Brian A. , Yu Lumeng J. , Khan Atif , Haffty Bruce , Goydos James S. , Chen Suzie
Published: November 2014

Approximately 50% of patients having metastatic melanoma develop brain metastases during the course of their illness. Evidence exists that melanoma cells have increased aptitude for the repair of sublethal DNA damage caused by ionizing radiation therapy. To address the radio‐resistance of melanoma, many groups adopted radiotherapy schedules that deliver larger daily fractions of radiation, but due to the risk of neurotoxicity, these large fractions cannot be delivered to the whole brain for patients with brain metastases. Here, we used orthotopic implanted GRM1 expressing human melanoma cell xenografts in mice, to demonstrate that animals receiving concurrent glutamate signaling blockade (riluzole) and radiation led to a decrease in intracranial tumor growth compared to either modality alone. These preclinical results suggest riluzole may cause radio‐sensitization that offers enhanced efficacy for a subset of human melanoma patients undergoing radiotherapy for brain metastasis.
Electronic Excitations in G‐quadruplexes Formed by the Human Telomeric Sequence: A Time‐Resolved Fluorescence Study
Authors: Changenet‐Barret Pascale , Hua Ying , Gustavsson Thomas , Markovitsi Dimitra
Published: November 2014

The present study deals with G‐quadruplexes formed by folding of the human telomeric sequence d(GGGTTAGGGTTAGGGTTAGGG), in presence of K+ cations, noted Tel21/K+. Fluorescence decays and fluorescence anisotropy decays, obtained upon excitation at 267 nm, are probed from femtosecond to nanosecond domains using two different detection techniques, fluorescence upconversion and time‐correlated single photon counting. The results are discussed in light of recent theoretical studies. It is shown that efficient energy transfer takes place among the bases on the femtosecond time scale, possible only via exciton states. The major part of the fluorescence originates from bright excited states having weak charge transfer character and decaying between 1 and 100 ps. Charge transfer states involving guanines in different tetrads decay mainly after 100 ps and emit at the red wing of the spectrum. The persistence of electronic excitations in Tel21/K+ is longer and the contribution of charge transfer states is more pronounced than what is observed for G‐quadruplexes formed by association of four d(TGGGT) strands and containing the same number of tetrads. This difference is due to the increased structural rigidity of monomolecular structures which reduces nonradiative deactivation pathways and favors collective effects.
A rare case of a natural contact zone in Morocco between an autopolyploid and an allopolyploid of Centaurea aspera with sterile tetraploid hybrids
Authors: Garmendia A. , Ferriol M. , Juarez J. , Zając A. , Kałużny K. , Merle H.
Published: November 2014

A new contact zone between Centaurea aspera and Centaurea seridis was found in Morocco. Chromosome counts and flow cytometry showed that both taxa were tetraploid (4x = 44). A literature review and morphometric analysis established that C. aspera corresponds to the autopolyploid C. aspera subsp. gentilii and C. seridis corresponds to the allopolyploid C. seridis var. auriculata. This contact area was compared with the homologous contact zones in Spain formed by the diploid C. aspera subsp. stenophylla and the tetraploid C. seridis subsp. maritima. Natural hybrids between parental species were frequent in both areas. In Spain, hybrids were triploid (from reduced gametes A and gamete AB), highly sterile and exerted a ‘triploid block’. In Morocco, cytometry showed that hybrids were tetraploid and, therefore, probably fertile, but all the capitula lacked achenes. It is likely that the resulting genome of the new tetraploid hybrid (AAAB), through the fusion of reduced gametes AA (from subsp. gentilii) and AB (from var. auriculata), could explain irregularities in meiosis through formation of aneuploid gametes and, therefore, infertility of the hybrid. Moroccan sterile tetraploid hybrids develop, but have the identical irregularities to Spanish triploids, probably due to the odd number of homologous chromosomes. The new hybrid is first described as C. x subdecurrens nothosubsp. paucispinus. In addition, distribution and ecological traits are analysed.
Coral aquaculture: applying scientific knowledge to ex situ production
Authors: Leal Miguel C. , Ferrier‐Pagès Christine , Petersen Dirk , Osinga Ronald
Published: November 2014

Coral aquaculture is an activity of growing interest due to the degradation of coral reefs worldwide and concomitant growing demand for corals by three industries: marine ornamental trade, pharmaceutical industry and reef restoration. Although captive breeding and propagation of corals is a well‐known activity among aquarium hobbyists and public aquariums, the link between coral science and aquaculture is still poorly developed. Research on coral biology has increased in the past decades and resulted in abundant scientific information that is pivotal to further advance coral aquaculture. This review presents a holistic overview of coral aquaculture in relation to coral biology, with particular focus on ex situ aquaculture. Success factors for commercial coral aquaculture are outlined, which include qualitative aspects, such as shape, coloration and natural product content, and quantitative parameters such as growth and volumetric productivity. Manipulation of environmental factors to maximize coral quality and volumetric productivity is thoroughly discussed, and a comprehensive overview of current propagation techniques is provided. Knowledge gaps are pinpointed to indicate directions for future research.
Effects of Topical Application of Misoprostol on Cervical Relaxation in Mares
Authors: McNaughten J , Pozor M , Macpherson M , Kelleman A , Woodward E , Troedsson M
Published: November 2014

Contents

Mares who have not delivered a foal early in life may experience limitations in cervical relaxation, primarily during oestrus. A closed cervix prevents intrauterine deposition of semen during natural breeding, may delay uterine clearance after insemination leading to intrauterine fluid accumulation in, and subsequent infertility. Therefore, a reliable pharmacological method of dilating the equine cervix would have practical application in veterinary medicine. The goal of this study was to investigate the effectiveness of topically applied, synthetic prostaglandin E1 analogue (PGE1) for stimulating dilation of the equine cervix. Ten mares in dioestrus were randomly assigned to one of two treatments in a single‐blind crossover study: (treatment) PGE1 gel (1000 mcg compounded misoprostol cream) applied topically to the external cervical os (n = 5), and (control) a vehicle cream applied topically to the external cervical os (n = 5). Transrectal palpation and ultrasonographic measurements of the cervix were performed prior to, six and 24 h post‐treatment. Digital measurements were taken, per vagina, at six and 24 h post‐treatment. Mares were monitored through the subsequent oestrous cycle for ovulation. Mares were assigned to the opposite treatment group such that each mare served as her own control (crossover). Data were analysed using parametric (split‐plot anova), as well as nonparametric (Kruskal–Wallis anova, Wilcoxon's rank‐sum test) methods. At six and 24 h there were no significant differences for tone, length, height, degree of relaxation or echotexture between control and PGE1 treated groups at the measured time points (p > 0.05). Topical cervical application of PGE1 did not induce a measurable degree of cervical relaxation under the conditions of this experiment.
Presence of Leptin and Its Receptor in the Hypothalamus, Uterus and Ovaries of Swine Females Culled with Distinct Ovarian Statuses and Parities
Authors: Moreira F , Gheller SMM , Mondadori RG , Varela Júnior AS , Corcini CD , Lucia T
Published: November 2014

Contents

Leptin acts on energy metabolism, affecting reproductive functions through activation of its receptors in the brain and in reproductive organs. This study compared the presence of leptin and its receptor (ObR‐b) in hypothalamus neurons, endometrial glands and oocytes of culled swine females across ovarian statuses and parities. Immunohistochemistry was done in samples of uterus, ovaries and hypothalamus from 28 culled females, using polyclonal antibodies antileptin andObR‐b. Immunolabelling was compared for sows categorized by parity at culling (0, 1, 2–4 and <4) and ovarian status (luteal and follicular phases of the oestrous cycle and with cysts). Immunolabelling for leptin andObR‐b in neurons and oocytes was weaker in females with cysts (p < 0.05) than in those at the follicular phase. In endometrial glands, leptin immunolabelling was less intense in females with cysts (p < 0.05), but immunolabelling forObR‐b was similar across ovarian statuses (p > 0.05). In sows culled with 2–4 parities, leptin immunolabelling in neurons and endometrial glands was more intense than in nulliparous females (p < 0.05). In comparison with sows culled at greater parities,ObR‐b immunolabelling for nulliparous females was less intense in endometrial glands and in oocytes (p < 0.05), but more intense in neurons (p < 0.05). Thus, in swine, the presence of leptin andObR‐b varies across parities and is more intense in the uterus, ovaries and hypothalamus of females that were cycling before culling than in those having cystic ovaries.
Analysis of Possible Influence of Conjugated Linoleic Acid on Growth Performance and Losses of Piglets
Authors: Hadaš Z , Čechová M , Nevrkla P
Published: November 2014

Contents

The aim of this work was to evaluate the effect of supplementing the feed ration for lactating sows with the conjugated linoleic acid (CLA) on the growth performance and losses of piglets from birth to weaning. The monitoring comprised 20 litters in control and 20 litters in experimental group of Czech Large White × Czech Landrace hybrid combination sows. The control group was given a standard feed mixture for lactating sows, and experimental group was fed with the feed mixture supplemented with 2% of CLA, from the day of farrowing to the weaning of piglets, that is for the time of 28 days. The results of the experiment indicate the significantly better parameters of the numbers of reared piglets in the experimental group and the related lower level of losses of piglets from birth to weaning (p < 0.01). However, the feed mixture for lactating sows enriched in conjugated linoleic acid had no significant effect on the growth performance of piglets from birth to weaning (p > 0.05). Sows in the experimental group showed earlier onset of post‐partal oestrus after weaning of piglets (p < 0.05). These findings demonstrate that the supplementation of diet for lactating sows with CLA can improve survival of piglets from birth to weaning and shortening of weaning‐to‐oestrous interval in sows.
Comparison of modern and ancient barite‐bearing acid‐sulphate soils using micromorphology, geochemistry and field relationships
Authors: Jennings Debra S. , Driese Steven G. , Dworkin Stephen I.
Published: November 2014

Although pedogenic barite has been documented in many modern soils and palaeosols, no actualistic studies on its formation have been reported. Because barite is stable over the entire range of pressure and temperature of the Earth's crust, it preserves reliable data about the original environment in which it formed. Pedogenic barite and barite‐bearing soils have been used as indicators of landscape stability, environmental conditions, climate and microbial acti‐vity. This study compares field data, micromorphology and stable isotope geochemistry of a barite‐bearing palaeosol from the Morrison Formation (Jurassic) and a modern analogue soil in south‐central Texas, USA. Morrison barite‐bearing palaeosols are over‐thickened cumulic palaeosols that developed in subaerially exposed lacustrine sediments during an extended lake contraction event. Lateral facies relationships document changes in hydrology and duration of episaturated conditions (perched water table above the Btg horizons) that correspond to differences in barite nodule morphology and abundance. Barite precipitation occurred at a redox boundary higher on the landscape after organic matter was completely oxidized. Sulphur isotope data indicate that the initial source of sulphur was soil organic matter. Meteoric water is the likely source of oxygen for the sulphate. Barium sourced from weathering feldspars and clays. The modern analogue displays similar catenary relationships, redox features and micromorphological characteristics compared to the Morrison palaeosols, suggesting that similar pedogenic processes led to barite precipitation. Synthesized data suggest that conditions favourable to barite‐bearing soil formation are low‐gradient basins that have received feldspar‐rich sediments (i.e. volcanically influenced basins), soils that developed near salt domes, soils that developed in exposed wetland or lacustrine sediments and coastal plain deposits. When studied in a well‐documented palaeogeographic context, barite‐bearing soils are valuable to palaeoclimate, palaeoenvironmental and palaeohydrological studies. Combined with regional interfluve palaeosols, barite‐bearing palaeosols may document temporal changes in drainage, surface stability, and accommodation consistent with sequence boundaries/maximum flooding surfaces and climate changes.
Sustainability and Resilience in Agrifood Systems: Reconnecting Agriculture, Food and the Environment
Authors: Lamine Claire
Published: November 2014

The sustainability and resilience of agrifood systems are generally considered either through the sustainable development paradigm, which focuses on the interactions between agriculture and the environment and often neglects consumption and food issues, or through the relocalisation paradigm, which prevails in the literature on alternative food systems and social movements. Because of its focus on direct producer‐consumer relations, the relocalisation perspective suggests a possible transition pathway, but does not fully address the diversity of interdependencies in agrifood systems (food being largely processed, distributed and provided by intermediaries) and therefore fails to effectively reconnect agriculture and food issues. This article shows the need to consider the possible reconnections between agricultural, food and environmental issues from a perspective that takes this diversity in agrifood systems into account. Such a perspective would go beyond the prevailing paradigm of relocalisation. Based on the analysis of recent scientific and public debates and on case studies carried out in France and Brazil, the article suggests a territorial agrifood systems perspective that takes account of the diverse actors and institutions involved in agriculture and food, and the diverse relations between agriculture, food and the environment that can contribute to the development of alternative and more resilient pathways.
Detection of Novel Reassortant Influenza A (H3N2) and H1N1 2009 Pandemic Viruses in Swine in Hanoi, Vietnam
Authors: Baudon E. , Poon L. L. , Dao T. D. , Pham N. T. , Cowling B. J. , Peyre M. , Nguyen K. V. , Peiris M.
Published: November 2014

From May to September 2013, monthly samples were collected from swine in a Vietnamese slaughterhouse for influenza virus isolation and serological testing. A(H1N1)pdm09 viruses and a novel H3N2 originating from reassortment between A(H1N1)pdm09 and novel viruses of the North American triple reassortant lineage were isolated. Serological results showed low seroprevalence for the novel H3N2 virus and higher seroprevalence for A(H1N1)pdm09 viruses. In addition, serology suggested that other swine influenza viruses are also circulating in Vietnamese swine.
Differential activation of receptors and signal pathways upon stimulation by different doses of sphingosine‐1‐phosphate in endothelial cells
Authors: Li Qiang , Chen Bo , Zeng Chong , Fan Aihui , Yuan Yongjun , Guo Xiaohua , Huang Xuliang , Huang Qiaobing
Published: November 2014

New Findings

What is the central question of this study?

Why do different doses of sphingosine‐1‐phosphate (S1P) induce distinct biological effects in endothelial cells?

What is the main finding and its importance?

S1P at physiological concentrations preserved endothelial barrier function by binding to S1P receptor 1, then triggering Ca2+ release from endoplasmic reticulum through phosphoinositide phospholipase C and inositol triphosphate, and consequently strengthening tight junction and F‐actin assembly through Rac1 activation. Excessive S1P induced endothelial malfunction by activating S1P receptor 2 and RhoA/ROCK pathway, causing F‐actin and tight junction disorganisation. Extracellular Ca2+ influx was involved in this process.

Sphingosine‐1‐phosphate (S1P) is a bioactive sphingolipid in plasma, and its plasma concentration can be adjusted through a complex metabolic process. The alterations in S1P levels and the activation of receptors collaboratively regulate distinct biological effects. This study was performed to investigate comparatively the effect of different concentrations of S1P on endothelial barrier function and to explore the roles of S1P receptors (S1PRs), Rho GTPases and calcium in S1P‐induced endothelial responses. Endothelial barrier function was studied using transendothelial electric resistance and a resistance meter in human umbilical vein endothelial cells. Specific agonists or antagonists were applied to control the activation of S1P receptors and the release of calcium from different cellular compartments. The results indicated that at physiological concentrations, S1P preserved endothelial barrier function by binding with S1PR1. The activation of S1PR1 triggered the release of intracellular Ca2+ from the endoplasmic reticulum through the PI–phospholipase C and inositol trisphosphate pathways. Consequently, the Rho GTPase Rac1 was activated, strengthening the assembly of tight junction proteins and F‐actin. However, excessive S1P induced endothelial barrier dysfunction by activating S1PR2 followed by the RhoA/RhoA kinase pathway, causing the disorganization of F‐actin and the disassembly of the tight junction protein ZO‐1. An influx of extracellular Ca2+ was involved in this process. These data suggest that physiological and excessive amounts of S1P induce different responses in human umbilical vein endothelial cells; the activation of the 1PR1–PLC–IP3R–Ca2+–Rac1 pathway governs the low‐dose S1P‐enhanced endothelial barrier integrity, and the activation of S1PR2–calcium influx–RhoA/ROCK dominates the high‐dose S1P‐induced endothelial monolayer hyperpermeability response.
Histological and biochemical outcomes of cardiac pathology in mdx mice with dietary quercetin enrichment
Authors: Ballmann Christopher , Hollinger Katrin , Selsby Joshua T. , Amin Rajesh , Quindry John C.
Published: November 2014

New Findings

What is the central question of this study?

Does dietary quercetin enrichment improve biochemical and histological outcomes in hearts from mdx mice?

What is the main finding and what is its importance?

Biochemical and histological findings suggest that chronic quercetin feeding of mdx mice may improve mitochondrial function and attenuate tissue pathology.

Patients with Duchenne muscular dystrophy suffer from cardiac pathology, which causes up to 40% of all deaths because of fibrosis and cardiac complications. Quercetin is a flavonol with anti‐inflammatory and antioxidant effects and is also an activator of peroxisome proliferator‐activated receptor γ coactivator 1α capable of antioxidant upregulation, mitochondrial biogenesis and prevention of cardiac complications. We sought to determine the extent to which dietary quercetin enrichment prevents (experiment 1) and rescues cardiac pathology (experiment 2) in mdx mice. In experiment 1, 3‐week‐old mdx mice were fed control chow (C3w6m, n = 10) or chow containing 0.2% quercetin for 6 months (Q3w6m, n = 10). In experiment 2, 3‐month‐old mdx mice were fed control chow (C3m6m, n = 10) or 0.2% chow containing 0.2% quercetin for 6 months (Q3m6m, n = 10). Hearts were excised for histological and biochemical analyses. In experiment 1, Western blot targets for mitochondrial biogenesis (cytochrome c, P = 0.007) and antioxidant expression (superoxide dismutase 2, P = 0.014) increased in Q3w6m mice compared with C3w6m. Histology revealed increased utrophin (P = 0.025) and decreased matrix metalloproteinase 9 abundance (P = 0.040) in Q3w6m mice compared with C3w6m. In experiment 2, relative (P = 0.023) and absolute heart weights (P = 0.020) decreased in Q3m6m mice compared with C3m6m. Indications of damage (Haematoxylin‐ and Eosin‐stained sections, P = 0.007) and Western blot analysis of transforming growth factor β1 (P = 0.009) were decreased in Q3m6m mice. Six months of quercetin feeding increased a mitochondrial biomarker, antioxidant protein and utrophin and decreased matrix metalloproteinase 9 in young mice. Given that these adaptations are associated with attenuated cardiac pathology and damage, the present findings may indicate that dietary quercetin enrichment attenuates dystrophic cardiac pathology, but physiological confirmation is needed.
The claudin‐16 channel gene is transcriptionally inhibited by 1,25‐dihydroxyvitamin D
Authors: Kladnitsky Orly , Rozenfeld Julia , Azulay‐Debby Hilla , Efrati Edna , Zelikovic Israel
Published: November 2014

New Findings

What is the central question of this study?

In the kidney, the bulk of the filtered Mg2+ is reabsorbed in the thick ascending limb by paracellular conductance, mediated by the tight junction protein, claudin‐16, which is encoded by the gene CLDN16. The role of 1,25‐dihydroxyvitamin D [1,25(OH)2VitD] in renal Mg2+ handling is unclear. We aimed to explore the molecular mechanisms underlying the effect of 1,25(OH)2VitD on claudin‐16‐mediated Mg2+ transport.

What is the main finding and its importance?

Paracellular, claudin‐16‐mediated Mg2+ transport is transcriptionally repressed by 1,25(OH)2VitD, probably via a Ca2+‐sensing receptor‐dependent mechanism. This renal effect of 1,25(OH)2VitD may serve as an adaptive mechanism to the 1,25(OH)2VitD‐induced enteric hyperabsorption of dietary Mg2+.

Magnesium is reabsorbed in the thick ascending limb by paracellular conductance, mediated by the CLDN16‐encoded tight junction protein, claudin‐16. However, the role of 1,25‐dihydroxyvitamin D [1,25(OH)2VitD] in renal Mg2+ handling is unclear. We have shown that Mg2+ depletion increases and 1,25(OH)2VitD inhibits CLDN16 transcription. We have now explored further the molecular mechanisms underlying the effect of 1,25(OH)2VitD on claudin‐16‐mediated Mg2+ transport. Adult mice received parenteral 1,25(OH)2VitD or 1,25(OH)2VitD combined with either high‐Mg2+ or low‐Mg2+ diets. Administration of 1,25(OH)2VitD enhanced urinary excretion of Mg2+ and Ca2+. The 1,25(OH)2VitD also increased renal Ca2+‐sensing receptor (CaSR) mRNA and decreased renal claudin‐16 and claudin‐19 mRNA and claudin‐16 protein, but did not affect renal claudin‐2 mRNA. The 1,25(OH)2VitD reversed the expected increase in claudin‐16 mRNA in Mg2+‐depleted animals. Comparably treated HEK 293 cells showed similar changes in claudin‐16 mRNA, but 1,25(OH)2VitD did not alter mRNA of the TRPM6 Mg2+ channel. A luciferase reporter vector containing 2.5 kb of 5′‐flanking DNA sequence from human CLDN16 (hCLDN16) was transfected into HEK 293 and OK cells. The hCLDN16 promoter activity was modestly decreased by 1,25(OH)2VitD, but markedly inhibited in HEK 293 cells coexpressing CaSR. Coexpression in OK cells of dominant‐negative CaSR completely abolished inhibition of hCLDN16 promoter activity by 1,25(OH)2VitD. The 1,25(OH)2VitD‐induced decrease in hCLDN16 promoter activity was attenuated in Mg2+‐depleted HEK 293 cells. In conclusion, 1,25(OH)2VitD transcriptionally inhibits claudin‐16 expression by a mechanism sensitive to CaSR and Mg2+. This renal effect of 1,25(OH)2VitD may serve as an adaptive response to the 1,25(OH)2VitD‐induced increase in intestinal Mg2+ absorption.
Investigation of CSAR 62, a new resist for electron beam lithography
Authors: Thoms Stephen , Macintyre Douglas S.
Published: November 2014

CSAR 62 is a new positive tone electron beam resist designed to have similar performance to ZEP520A in resolution, speed, and etch resistance. In this paper, the authors have used the resist to carry out high resolution electron beam lithography and as a mask for reactive ion etching on dielectrics, gallium arsenide, and silicon substrates coated with a 160 nm film of aluminum. Comparisons have been made between the results obtained using CSAR 62, ZEP520A, and polymethylmethacrylate. The authors conclude that CSAR 62 does demonstrate similar resolution, sensitivity, and etch resistance as ZEP520A but also gives rise to substantial resist residuals after development. These are almost entirely eliminated by using an alternative developer.
Mechanism and applications of helium transmission milling in thin membranes
Authors: Tan Shida , Klein Kate , Shima Darryl , Livengood Rick , Mutunga Eva , Vladár András
Published: November 2014

Focused ion beam interaction profiles and nanomachining mechanisms are very different for membrane and bulk samples. In this work, a detailed empirical study was carried out to understand these differences by observing the progression of helium ion milling in silicon single crystalline membranes and bulk samples using cross-sectional transmission electron microscopy. The components of backward sputter yield and forward sputter yield unique to the membrane samples were observed, analyzed, and contrasted with the bulk sample sputter yield.
Marine Cyanophages Demonstrate Biogeographic Patterns throughout the Global Ocean
Authors: Huang Sijun , Zhang Si , Jiao Nianzhi , Chen Feng
Published: November 2014

Myoviruses and podoviruses that infect cyanobacteria are the two major groups of marine cyanophages, but little is known of how their phylogenetic lineages are distributed in different habitats. In this study, we analyzed the phylogenetic relationships of cyanopodoviruses and cyanomyoviruses based on the existing genomes. The 28 cyanomyoviruses were classified into four clusters (I to IV), and 19 of the 20 cyanopodoviruses were classified into two clusters, MPP-A and MPP-B, with four subclusters within cluster MPP-B. These genomes were used to recruit cyanophage-like fragments from microbial and viral metagenomes to estimate the relative abundances of these cyanophage lineages. Our results showed that cyanopodoviruses and cyanomyoviruses are both abundant in various marine environments and that clusters MPP-B, II and III appear to be the most dominant lineages. Cyanopodoviruses and cluster I and IV cyanomyoviruses exhibited habitat-related variability in their relative levels of abundance, while cluster II and III cyanomyoviruses appeared to be consistently dominant in various habitats. Multivariate analyses showed that reads that mapped to
Synechococcus
phages and
Prochlorococcus
phages had distinct distribution patterns that were significantly correlated to those of
Synechococcus
and
Prochlorococcus
, respectively. The Mantel test also revealed a strong correlation between the community compositions of cyanophages and picocyanobacteria. Given that cyanomyoviruses tend to have a broad host range and some can cross-infect
Synechococcus
and
Prochlorococcus
, while cyanopodoviruses are commonly host specific, the observation that their community compositions both correlated significantly with that of picocyanobacteria was unexpected. Although cyanomyoviruses and cyanopodoviruses differ in host specificity, their biogeographic distributions are likely both constrained by the picocyanobacterial community.
Screening of High-Level 4-Hydroxy-2 (or 5)-Ethyl-5 (or 2)-Methyl-3(2
H
)-Furanone-Producing Strains from a Collection of Gene Deletion Mutants of Saccharomyces cerevisiae
Authors: Uehara Kenji , Watanabe Jun , Akao Takeshi , Watanabe Daisuke , Mogi Yoshinobu , Shimoi Hitoshi
Published: November 2014

4-Hydroxy-2 (or 5)-ethyl-5 (or 2)-methyl-3(2
H
)-furanone (HEMF) is an important flavor compound that contributes to the sensory properties of many natural products, particularly soy sauce and soybean paste. The compound exhibits a caramel-like aroma and several important physiological activities, such as strong antioxidant activity. HEMF is produced by yeast species in soy sauce manufacturing; however, the enzymes involved in HEMF production remain unknown, hindering efforts to breed yeasts with high-level HEMF production. In this study, we identified high-level HEMF-producing mutants among a
Saccharomyces cerevisiae
gene deletion mutant collection. Fourteen deletion mutants were screened as high-level HEMF-producing mutants, and the
ADH1
gene deletion mutant (
adh1
Δ) exhibited the maximum HEMF production capacity. Further investigations of the
adh1
Δ mutant implied that acetaldehyde accumulation contributes to HEMF production, agreeing with previous findings. Therefore, acetaldehyde might be a precursor for HEMF. The
ADH1
gene deletion mutant of
Zygosaccharomyces rouxii
, which is the dominant strain of yeast found during soy sauce fermentation, also produces HEMF effectively, suggesting that acetaldehyde accumulation might be a benchmark for breeding industrial yeasts with excellent HEMF production abilities.
Immunoprecipitation of Native Botulinum Neurotoxin Complexes from Clostridium botulinum Subtype A Strains
Authors: Lin Guangyun , Tepp William H. , Bradshaw Marite , Fredrick Chase M. , Johnson Eric A.
Published: November 2014

Botulinum neurotoxins (BoNTs) naturally exist as components of protein complexes containing nontoxic proteins. The nontoxic proteins impart stability of BoNTs in the gastrointestinal tract and during purification and handling. The two primary neurotoxin complexes (TCs) are (i) TC1, consisting of BoNT, nontoxin-nonhemagglutinin (NTNH), and hemagglutinins (HAs), and (ii) TC2, consisting of BoNT and NTNH (and possibly OrfX proteins). In this study, BoNT/A subtypes A1, A2, A3, and A5 were examined for the compositions of their TCs in culture extracts using immunoprecipitation (IP). IP analyses showed that BoNT/A1 and BoNT/A5 form TC1s, while BoNT/A2 and BoNT/A3 form TC2s. A
Clostridium botulinum
host strain expressing recombinant BoNT/A4 (normally present as a TC2) from an extrachromosomal plasmid formed a TC1 with complexing proteins from the host strain, indicating that the HAs and NTNH encoded on the chromosome associated with the plasmid-encoded BoNT/A4. Strain NCTC 2916 (A1/silent B1), which carries both an
ha
silent
bont/b
cluster and an
orfX bont
/
a1
cluster, was also examined. IP analysis revealed that NCTC 2916 formed only a TC2 containing BoNT/A1 and its associated NTNH. No association between BoNT/A1 and the nontoxic proteins from the silent
bont/b
cluster was detected, although the HAs were expressed as determined by Western blotting analysis. Additionally, NTNH and HAs from the silent
bont/b
cluster did not form a complex in NCTC 2916. The stabilities of the two types of TC differed at various pHs and with addition of KCl and NaCl. TC1 complexes were more stable than TC2 complexes. Mouse serum stabilized TC2, while TC1 was unaffected.
Reproducible and Quantitative Model of Infection of Dermacentor variabilis with the Live Vaccine Strain of Francisella tularensis
Authors: Coburn Jenifer , Maier Tamara , Casey Monika , Padmore Lavinia , Sato Hiromi , Frank Dara W.
Published: November 2014

Pathogen life cycles in mammalian hosts have been studied extensively, but studies with arthropod vectors represent considerable challenges. In part this is due to the difficulty of delivering a reproducible dose of bacteria to follow arthropod-associated replication. We have established reproducible techniques to introduce known numbers of
Francisella tularensis
strain LVS from mice into
Dermacentor variabilis
nymphs. Using this model infection system, we performed dose-response infection experiments and followed bacterial replication through the molt to adults and at later time points. During development to adults, bacteria replicate to high numbers and can be found associated with the gut tissues, salivary glands, and hemolymph of adult ticks. Further, we can transmit a mutant of LVS (LVS Δ
purMCD
) that cannot replicate in macrophages
in vitro
or in mice to nymphs. Our data show that the LVS Δ
purMCD
mutant cannot be transstadially transmitted from nymphs to adult ticks. We then show that a plasmid-complemented strain of this mutant is recoverable in adult ticks and necessary for bacterial replication during the molt. In a mixed-infection assay (Δ
purMCD
mutant versus Δ
purMCD
complement), 98% of the recovered bacteria retained the plasmid marker. These data suggest that the Δ
purMCD
mutation cannot be rescued by the presence a complemented strain in a mixed infection. Importantly, our infection model provides a platform to test specific mutants for their replication in ticks, perform competition studies, and use other genetic techniques to identify
F. tularensis
genes that are expressed or required in this unique environment.
Phyllosphere Bacterial Community of Floating Macrophytes in Paddy Soil Environments as Revealed by Illumina High-Throughput Sequencing
Authors: Xie Wan-Ying , Su Jian-Qiang , Zhu Yong-Guan
Published: November 2014

The phyllosphere of floating macrophytes in paddy soil ecosystems, a unique habitat, may support large microbial communities but remains largely unknown. We took
Wolffia australiana
as a representative floating plant and investigated its phyllosphere bacterial community and the underlying driving forces of community modulation in paddy soil ecosystems using Illumina HiSeq 2000 platform-based 16S rRNA gene sequence analysis. The results showed that the phyllosphere of
W. australiana
harbored considerably rich communities of bacteria, with
Proteobacteria
and
Bacteroidetes
as the predominant phyla. The core microbiome in the phyllosphere contained genera such as
Acidovorax
,
Asticcacaulis
,
Methylibium
, and
Methylophilus
. Complexity of the phyllosphere bacterial communities in terms of class number and α-diversity was reduced compared to those in corresponding water and soil. Furthermore, the bacterial communities exhibited structures significantly different from those in water and soil. These findings and the following redundancy analysis (RDA) suggest that species sorting played an important role in the recruitment of bacterial species in the phyllosphere. The compositional structures of the phyllosphere bacterial communities were modulated predominantly by water physicochemical properties, while the initial soil bacterial communities had limited impact. Taken together, the findings from this study reveal the diversity and uniqueness of the phyllosphere bacterial communities associated with the floating macrophytes in paddy soil environments.