bluuebunny/crossref_metadata_2025 huggingface dataset:
HIV treatment for prevention
Authors: Ambrosioni Juan , Calmy Alexandra , Hirschel Bernard
Published: May 2011

“No virus, no transmission.” Studies have repeatedly shown that viral load (the quantity of virus present in blood and sexual secretions) is the strongest predictor of HIV transmission during unprotected sex or transmission from infected mother to child.

Effective treatment lowers viral load to undetectable levels. If one could identify and treat all HIV‐infected people immediately after infection, the HIV/AIDS epidemic would eventually disappear.

Such a radical solution is currently unrealistic. In reality, not all people get tested, especially when they fear stigma and discrimination. Thus, not all HIV‐infected individuals are known. Of those HIV‐positive individuals for whom the diagnosis is known, not all of them have access to therapy, agree to be treated, or are taking therapy effectively. Some on effective treatment will stop, and in others, the development of resistance will lead to treatment failure. Furthermore, resources are limited: should we provide drugs to asymptomatic HIV‐infected individuals without indication for treatment according to guidelines in order to prevent HIV transmission at the risk of diverting funding from sick patients in urgent need?

In fact, the preventive potential of anti‐HIV drugs is unknown. Modellers have tried to fill the gap, but models differ depending on assumptions that are strongly debated. Further, indications for antiretroviral treatments expand; in places like Vancouver and San Francisco, the majority of HIV‐positive individuals are now under treatment, and the incidence of new HIV infections has recently fallen. However, correlation does not necessarily imply causation. Finally, studies in couples where one partner is HIV‐infected also appear to show that treatment reduces the risk of transmission.

More definite studies, where a number of communities are randomized to either receive the “test‐and‐treat” approach or continue as before, are now in evaluation by funding agencies. Repeated waves of testing would precisely measure the incidence of HIV infection. Such trials face formidable logistical, practical and ethical obstacles. However, without definitive data, the intuitive appeal of “test‐and‐treat” is unlikely to translate into action on a global scale. In the meantime, based on the available evidence, we must strive to provide treatment to all those in medical need under the current medical guidelines. This will lead to a decrease in HIV transmission while “test‐and‐treat” is fully explored in prospective clinical trials.
Albuminuria and Diabetic Retinopathy in Type 2 Diabetes Mellitus Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular Genetic Study (SN-DREAMS, report 12)
Authors: Rani Padmaja K , Raman Rajiv , Gupta Aditi , Pal Swakshyar S , Kulothungan Vaitheeswaran , Sharma Tarun
Published: May 2011

Background

The concordance of microalbuminuria and diabetic retinopathy (DR) has been well reported in persons with type 1 diabetes; however, for type 2 diabetes, there is paucity of data especially from population-based studies. The aim of this study was to estimate the prevalence of albuminuria (micro - and macroalbuminuria) among persons with type 2 diabetes and determine its role as a risk factor for presence and severity of DR.

Methods

A population-based cross sectional study was conducted in cohort of 1414 subjects with type 2 diabetes from Chennai metropolis. All the subjects underwent comprehensive eye examination including 45 degrees four-field stereoscopic digital photography. DR was clinically graded using Early Treatment Diabetic Retinopathy Study scales. A morning urine sample was tested for albuminuria. Subjects were considered to have microalbuminuria, if the urinary albumin excretion was between 30 and 300 mg/24 hours, and macroalbuminuria at more than 300 mg/24 hours. The statistical software used was SPSS for Windows, Chicago, IL. Student t-test for comparing continuous variables, and χ
2 test, to compare proportions amongst groups were used.

Results

The prevalence of microalbuminuria in the study subjects was 15.9% (226/1414), and that of macroalbuminuria, 2.7% (38/1414). Individuals with macroalbuminuria in comparison to micro- or normoalbuminuria showed a greater prevalence of DR (60.5% vs. 31.0% vs. 14.1%, p < 0.001), and also a greater severity of the disease (60.9% vs. 21.4 vs. 9.9, p < 0.001).

Conclusions

Every 6th individual in the population of type 2 diabetes is likely to have albuminuria. Subjects with microalbuminuria were around 2 times as likely to have DR as those without microalbuminuria, and this risk became almost 6 times in the presence of macroalbuminuria.
Hyperglycaemia and apoptosis of microglial cells in human septic shock
Authors: Polito Andrea , Brouland Jean-Philippe , Porcher Raphael , Sonneville Romain , Siami Shidasp , Stevens Robert D , Guidoux Céline , Maxime Virginie , de la Grandmaison Geoffroy Lorin , Chrétien Fabrice C , Gray Françoise , Annane Djillali , Sharshar Tarek
Published: May 2011

Introduction

The effect of hyperglycaemia on the brain cells of septic shock patients is unknown. The objective of this study was to evaluate the relationship between hyperglycaemia and apoptosis in the brains of septic shock patients.

Methods

In a prospective study of 17 patients who died from septic shock, hippocampal tissue was assessed for neuronal ischaemia, neuronal and microglial apoptosis, neuronal Glucose Transporter (GLUT) 4, endothelial inducible Nitric Oxide Synthase (iNOS), microglial GLUT5 expression, microglial and astrocyte activation. Blood glucose (BG) was recorded five times a day from ICU admission to death. Hyperglycaemia was defined as a BG 200 mg/dL g/l and the area under the BG curve (AUBGC) > 2 g/l was assessed.

Results

Median BG over ICU stay was 2.2 g/l. Neuronal apoptosis was correlated with endothelial iNOS expression (rho = 0.68, P = 0.04), while microglial apoptosis was associated with AUBGC > 2 g/l (rho = 0.70; P = 0.002). Neuronal and microglial apoptosis correlated with each other (rho = 0.69, P = 0.006), but neither correlated with the duration of septic shock, nor with GLUT4 and 5 expression. Neuronal apoptosis and ischaemia tended to correlate with duration of hypotension.

Conclusions

In patients with septic shock, neuronal apoptosis is rather associated with iNOS expression and microglial apoptosis with hyperglycaemia, possibly because GLUT5 is not downregulated. These data provide a mechanistic basis for understanding the neuroprotective effects of glycemic control.
Epigenetics, bioenergetics, and microRNA coordinate gene-specific reprogramming during acute systemic inflammation
Authors: McCall Charles E , El Gazzar Mohamed , Liu Tiefu , Vachharajani Vidula , Yoza Barbara
Published: May 2011

Acute systemic inflammation from infectious and noninfectious etiologies has stereotypic features that progress through an initiation (proinflammatory) phase, an adaptive (anti-inflammatory) phase, and a resolution (restoration of homeostasis) phase. These phase-shifts are accompanied by profound and predictable changes in gene expression and metabolism. Here, we review the emerging concept that the temporal phases of acute systemic inflammation are controlled by an integrated bioenergy and epigenetic bridge that guides the timing of transcriptional and post-transcriptional processes of specific gene sets. This unifying connection depends, at least in part, on redox sensor NAD+-dependent deacetylase, Sirt1, and a NF-κB-dependent p65 and RelB feed-forward and gene-specific pathway that generates silent facultative heterochromatin and active euchromatin. An additional level of regulation for gene-specific reprogramming is generated by differential expression of miRNA that directly and indirectly disrupts translation of inflammatory genes. These molecular reprogramming circuits generate a dynamic chromatin landscape that temporally defines the course of acute inflammation.
Minireview: The Stem Cell Next Door: Skeletal and Hematopoietic Stem Cell “Niches” in Bone
Authors: Bianco Paolo
Published: May 2011

Long known to be home to hematopoietic stem cells (HSC), the bone/bone marrow organ and its cellular components are directly implicated in regulating hematopoiesis and HSC function. Over the past few years, advances on the identity of HSC “niche” cells have brought into focus the role of cells of osteogenic lineage and of marrow microvessels. At the same time, the identity of self-renewing multipotent skeletal progenitors (skeletal stem cells, also known as mesenchymal stem cells) has also been more precisely defined, along with the recognition of their own microvascular niche. The two sets of evidence converge in delineating a picture in which two kinds of stem cells share an identical microanatomical location in the bone/bone marrow organ. This opens a new view on the manner in which the skeleton and hematopoiesis can cross-regulate via interacting stem cells but also a novel view of our general concept of stem cell niches.
Phosphorylation of CSF-1R Y721 mediates its association with PI3K to regulate macrophage motility and enhancement of tumor cell invasion
Authors: Sampaio Natalia G. , Yu Wenfeng , Cox Dianne , Wyckoff Jeffrey , Condeelis John , Stanley E. Richard , Pixley Fiona J.
Published: May 2011

Colony stimulating factor-1 (CSF-1) regulates macrophage morphology and motility, as well as mononuclear phagocytic cell proliferation and differentiation. The CSF-1 receptor (CSF-1R) transduces these pleiotropic signals through autophosphorylation of eight intracellular tyrosine residues. We have used a novel bone-marrow-derived macrophage cell line system to examine specific signaling pathways activated by tyrosine-phosphorylated CSF-1R in macrophages. Screening of macrophages expressing a single species of CSF-1R with individual tyrosine-to-phenylalanine residue mutations revealed striking morphological alterations upon mutation of Y721. M−/−.Y721F cells were apolar and ruffled poorly in response to CSF-1. Y721-P-mediated CSF-1R signaling regulated adhesion and actin polymerization to control macrophage spreading and motility. Moreover, the reduced motility of M−/− .Y721F macrophages was associated with their reduced capacity to enhance carcinoma cell invasion. Y721 phosphorylation mediated the direct association of the p85 subunit of phosphoinositide 3-kinase (PI3K) with the CSF-1R, but not that of phospholipase C (PLC) γ2, and induced polarized PtdIns(3,4,5)P3 production at the putative leading edge, implicating PI3K as a major regulator of CSF-1-induced macrophage motility. The Y721-P-motif-based motility signaling was at least partially independent of both Akt and increased Rac and Cdc42 activation but mediated the rapid and transient association of an unidentified ~170 kDa phosphorylated protein with either Rac-GTP or Cdc42-GTP. These studies identify CSF-1R-Y721-P–PI3K signaling as a major pathway in CSF-1-regulated macrophage motility and provide a starting point for the discovery of the immediate downstream signaling events.
Samp1 is functionally associated with the LINC complex and A-type lamina networks
Authors: Gudise Santhosh , Figueroa Ricardo A. , Lindberg Robert , Larsson Veronica , Hallberg Einar
Published: May 2011

The transmembrane inner nuclear membrane (INM) protein Samp1 is required for anchoring centrosomes near the nuclei. Using high-resolution fluorescence microscopy we show that Samp1 is distributed in a distinct and characteristic pattern in the nuclear envelope (NE), where it partially colocalizes with the LINC complex protein Sun1. By studying the localization of Samp1 deletion mutants and fusion proteins, we conclude that the cysteine-rich N-terminal half of Samp1 is nucleoplasmically exposed and is responsible for targeting to the INM. It contains four conserved CxxC motifs with the potential to form zinc fingers. The distribution of cysteine-to-alanine substitution mutants, designed to prevent zinc finger formation, showed that NE localization of Samp1 depends on intact CxxC motifs. Overexpression of Samp1 zinc finger mutants produced an abnormal dominant phenotype characterized by disrupted organization of a selective subset NE proteins, including emerin, Sun1, endogenous Samp1 and, in some cases, lamin A/C, but not lamin B, Sun2 or nucleoporins. Silencing of Samp1 expression showed that emerin depends on Samp1 for its correct localization in the NE. Our results demonstrate that Samp1 is functionally associated with the LINC complex protein Sun1 and proteins of the A-type lamina network.
PLD1 rather than PLD2 regulates phorbol-ester-, adhesion-dependent and Fcγ-receptor-stimulated ROS production in neutrophils
Authors: Norton Laura J. , Zhang Qifeng , Saqib Khalid M. , Schrewe Heinrich , Macura Karol , Anderson Karen E. , Lindsley Craig W. , Brown H. Alex , Rudge Simon A. , Wakelam Michael J. O.
Published: May 2011

The signalling lipid phosphatidic acid (PA) is generated by the hydrolysis of phosphatidylcholine (PC), which is catalysed by phospholipase D (PLD) enzymes. Neutrophils, important cells of the innate immune system, maintain the body's defence against infection. Previous studies have implicated PLD-generated PA in neutrophil function; these have relied heavily on the use of primary alcohols to act as inhibitors of PA production. The recent development of isoform-selective small molecule inhibitors and the generation of a knockout mouse model provide us with accurate tools to study the role of PLDs in neutrophil responses. We show that PLD1 is a regulator of phorbol-ester-, chemoattractant, adhesion-dependent and Fcγ-receptor-stimulated production of reactive oxygen species (ROS) in neutrophils. Significantly we found that this role of PLD is isoform specific: the absence of PLD2 does not negatively affect these processes. Contrary to expectation, other functions required for an efficient immune response operate effectively in Pld2-deficient neutrophils or when both isoforms are inhibited pharmacologically. We conclude that although PLD1 does have important regulatory roles in neutrophils, the field has been confused by the use of primary alcohols; now that gold standard Pld-knockout mouse models are available, previous work might need to be reassessed.
Essential role of PACSIN2/syndapin-II in caveolae membrane sculpting
Authors: Senju Yosuke , Itoh Yuzuru , Takano Kazunori , Hamada Sayaka , Suetsugu Shiro
Published: May 2011

Caveolae are flask-shaped invaginations of the plasma membrane that are associated with tumor formation, pathogen entry and muscular dystrophy, through the regulation of lipids, signal transduction and endocytosis. Caveolae are generated by the fusion of caveolin-1-containing vesicles with the plasma membrane, which then participate in endocytosis via dynamin. Proteins containing membrane-sculpting F-BAR (or EFC) domains organize the membrane in clathrin-mediated endocytosis. Here, we show that the F-BAR protein PACSIN2 sculpts the plasma membrane of the caveola. The PACSIN2 F-BAR domain interacts directly with caveolin-1 by unmasking autoinhibition of PACSIN2. Furthermore, the membrane invaginations induced by the PACSIN2 F-BAR domain contained caveolin-1. Knockdown of PACSIN2 resulted in abnormal morphology of caveolin-1-associated plasma membranes, presumably as a result of decreased recruitment of dynamin-2 to caveolin-1. These results indicate that PACSIN2 mediates membrane sculpting by caveolin-1 in caveola morphology and recruits dynamin-2 for caveola fission.
Dynamic interaction of Y RNAs with chromatin and initiation proteins during human DNA replication
Authors: Zhang Alice Tianbu , Langley Alexander R. , Christov Christo P. , Kheir Eyemen , Shafee Thomas , Gardiner Timothy J. , Krude Torsten
Published: May 2011

Non-coding Y RNAs are required for the initiation of chromosomal DNA replication in mammalian cells. It is unknown how they perform this function or if they associate with a nuclear structure during DNA replication. Here, we investigate the association of Y RNAs with chromatin and their interaction with replication proteins during DNA replication in a human cell-free system. Our results show that fluorescently labelled Y RNAs associate with unreplicated euchromatin in late G1 phase cell nuclei before the initiation of DNA replication. Following initiation, Y RNAs are displaced locally from nascent and replicated DNA present in replication foci. In intact human cells, a substantial fraction of endogenous Y RNAs are associated with G1 phase nuclei, but not with G2 phase nuclei. Y RNAs interact and colocalise with the origin recognition complex (ORC), the pre-replication complex (pre-RC) protein Cdt1, and other proteins implicated in the initiation of DNA replication. These data support a molecular ‘catch and release’ mechanism for Y RNA function during the initiation of chromosomal DNA replication, which is consistent with Y RNAs acting as replication licensing factors.
The effect of acclimation to hypoxia and sustained exercise on subsequent hypoxia tolerance and swimming performance in goldfish (Carassius auratus)
Authors: Fu Shi-Jian , Brauner Colin J. , Cao Zhen-Dong , Richards Jeffrey G. , Peng Jiang-Lan , Dhillon Rashpal , Wang Yu-Xiang
Published: May 2011

The objective of this study was to determine whether acclimation to hypoxia and sustained exercise would increase hypoxia tolerance (as indicated by a decrease in critical oxygen tension, Pcrit) and swimming performance in goldfish (Carassius auratus), and to investigate the relationship between changes in performance and gill remodelling and tissue metabolic capacity. Goldfish were acclimated to either hypoxia (48 h at 0.3 mg O2 l–1) or sustained exercise (48 h at 70% of critical swimming speed, Ucrit) and then Pcrit and Ucrit were determined in normoxia (10 mg O2 l–1) and hypoxia (1 mg O2 l–1) and compared with values from control fish. Acclimation to both hypoxia and sustained exercise improved hypoxia tolerance (Pcrit was reduced by 49% and 39%, respectively), which was associated with an increase in lamellar surface area (71% and 43%, respectively) and an increase in blood [Hb] (26% in both groups). Exercise acclimation also resulted in a decrease in routine (). Acclimation to both hypoxia and sustained exercise resulted in a significant increase in Ucrit in hypoxia (18% and 17%, respectively), which was associated with an increase in maximal O2 consumption rate at Ucrit (; 35% and 39%, respectively). While hypoxia acclimation resulted in an increase in Ucrit in normoxia, acclimation to sustained exercise did not improve subsequent swimming performance in normoxia. This lack of improvement was possibly due to depleted oxidizable substrates during exercise acclimation.
Static electric fields modify the locomotory behaviour of cockroaches
Authors: Jackson Christopher W. , Hunt Edmund , Sharkh Suleiman , Newland Philip L.
Published: May 2011

Static electric fields are found throughout the environment and there is growing interest in how electric fields influence insect behaviour. Here we have analysed the locomotory behaviour of cockroaches (Periplaneta americana) in response to static electric fields at levels equal to and above those found in the natural environment. Walking behaviour (including velocity, distance moved, turn angle and time spent walking) were analysed as cockroaches approached an electric field boundary in an open arena, and also when continuously exposed to an electric field. On approaching an electric field boundary, the greater the electric field strength the more likely a cockroach would be to turn away from, or be repulsed by, the electric field. Cockroaches completely exposed to electric fields showed significant changes in locomotion by covering less distance, walking slowly and turning more often. This study highlights the importance of electric fields on the normal locomotory behaviour of insects.
The ontogeny of regulatory control of the rainbow trout (Oncorhynchus mykiss) heart and how this is influenced by chronic hypoxia exposure
Authors: Miller Silvana C. , Gillis Todd E. , Wright Patricia A.
Published: May 2011

Salmonid embryos develop in cool waters over relatively long periods of time. Interestingly, hypoxic conditions have been found to be relatively common in some nesting sites (redds). The goals of this study were to determine the ontogeny of cardiac regulation in rainbow trout early life stages and how this is influenced by chronic hypoxia. The heart rate response to cholinergic and adrenergic receptor stimulation or inhibition was measured in individuals reared in normoxic (100% O2 saturation) or hypoxic (30% O2 saturation) conditions from fertilization to embryonic stages 22, 26 and 29, and larval stages 30 and 32. In normoxia, heart rate increased in response to β-adrenergic receptor stimulation (isoproterenol) as early as embryonic stage 22, and decreased with the antagonist propranolol after this stage. Cholinergic stimulation (acetylcholine) was ineffective at all stages, but atropine (acetylcholine antagonist) increased heart rate at larval stage 32. This demonstrates that cardiac β-adrenergic receptors are functional at early life stages, while cholinergic receptors are not responsive until after hatching. Collectively, embryos had cardio-acceleration control mechanisms in place just after the heartbeat stage, while cardio-inhibitory control was not functional until after hatching. Chronic hypoxia exposure triggered bradycardia, increased the response to adrenergic stimulation in embryos and larvae, and delayed the onset of cholinergic control in larvae. In non-motile stages, therefore, survival in chronic low oxygen may depend on the ability to alter the cardiac ontogenic program to meet the physiological requirements of the developing fish.
Sound radiation and wing mechanics in stridulating field crickets (Orthoptera: Gryllidae)
Authors: Montealegre-Z Fernando , Jonsson Thorin , Robert Daniel
Published: May 2011

Male field crickets emit pure-tone mating calls by rubbing their wings together. Acoustic radiation is produced by rapid oscillations of the wings, as the right wing (RW), bearing a file, is swept across the plectrum borne on the left wing (LW). Earlier work found the natural resonant frequency (fo) of individual wings to be different, but there is no consensus on the origin of these differences. Previous studies suggested that the frequency along the song pulse is controlled independently by each wing. It has also been argued that the stridulatory file has a variable fo and that the frequency modulation observed in most species is associated with this variability. To test these two hypotheses, a method was developed for the non-contact measurement of wing vibrations during singing in actively stridulating Gryllus bimaculatus. Using focal microinjection of the neuroactivator eserine into the cricket's brain to elicit stridulation and micro-scanning laser Doppler vibrometry, we monitored wing vibration in actively singing insects. The results show significantly lower fo in LWs compared with RWs, with the LW fo being identical to the sound carrier frequency (N=44). But during stridulation, the two wings resonate at one identical frequency, the song carrier frequency, with the LW dominating in amplitude response. These measurements also demonstrate that the stridulatory file is a constant resonator, as no variation was observed in fo along the file during sound radiation. Our findings show that, as they engage in stridulation, cricket wings work as coupled oscillators that together control the mechanical oscillations generating the remarkably pure species-specific song.
Kinematic and behavioral evidence for a distinction between trotting and ambling gaits in the cockroachBlaberus discoidalis
Authors: Bender John A. , Simpson Elaine M. , Tietz Brian R. , Daltorio Kathryn A. , Quinn Roger D. , Ritzmann Roy E.
Published: May 2011

Earlier observations had suggested that cockroaches might show multiple patterns of leg coordination, or gaits, but these were not followed by detailed behavioral or kinematic measurements that would allow a definite conclusion. We measured the walking speeds of cockroaches exploring a large arena and found that the body movements tended to cluster at one of two preferred speeds, either very slow (<10 cm s–1) or fairly fast (∼30 cm s–1). To highlight the neural control of walking leg movements, we experimentally reduced the mechanical coupling among the various legs by tethering the animals and allowing them to walk in place on a lightly oiled glass plate. Under these conditions, the rate of stepping was bimodal, clustering at fast and slow speeds. We next used high-speed videos to extract three-dimensional limb and joint kinematics for each segment of all six legs. The angular excursions and three-dimensional motions of the leg joints over the course of a stride were variable, but had different distributions in each gait. The change in gait occurs at a Froude number of ∼0.4, a speed scale at which a wide variety of animals show a transition between walking and trotting. We conclude that cockroaches do have multiple gaits, with corresponding implications for the collection and interpretation of data on the neural control of locomotion.
Some like it hot: the effects of climate change on reproduction, immune function and disease resistance in the cricketGryllus texensis
Authors: Adamo Shelley A. , Lovett Maggie M. E.
Published: May 2011

In many parts of the world, climate change is increasing the frequency and severity of heat waves. How do heat waves impact short-lived poikilotherms such as insects? In the cricket, Gryllus texensis, 6 days of elevated temperatures (i.e. 7°C above the average field temperature and 5°C above their preferred temperature) resulted in increased egg laying, faster egg development and greater mass gain. The increased temperature also increased activity of phenoloxidase and lysozyme-like enzymes, two immune-related enzymes, and enhanced resistance to the Gram-negative bacterium Serratia marcescens. When given a sublethal S. marcescens infection, G. texensis maintained increased reproductive output at the elevated temperature (33°C). These data suggest that heat waves could result in more numerous, disease resistant, crickets. However, resistance to the Gram-positive bacterium, Bacillus cereus was lower at temperatures above or below the average field temperature (26°C). A sublethal infection with B. cereus reduced egg laying at all temperatures and suppressed the increase in egg laying induced by higher temperatures. These results suggest that for some species–pathogen interactions, increased temperatures can induce trade-offs between reproduction and disease resistance. This result may partly explain why G. texensis prefers temperatures lower than those that produce maximal reproductive output and enhanced immune function.
Life-cycle assessment of bioenergy production systems from oilseed rape crops
Authors: Cocco D
Published: May 2011

This article is concerned with a life-cycle assessment (LCA) study of bioenergy production systems based on oilseed rape cultivation. In particular, the study compares the production of biodiesel via transesterification of rapeseed oil, power generation through diesel engines fuelled by raw vegetable oil, and power generation through steam power plants fuelled by the overall aboveground biomass.

The results of the LCA study show that bioenergy systems based on power generation perform better than bioenergy systems based on biodiesel production. In particular, the best energy and environmental performance are achieved with steam power plants fuelled by the overall aboveground biomass, which allow a reduction of primary energy consumption by about 75 per cent, the greenhouse impact by about 60 per cent, and the acidification impact by about 52 per cent with respect to conventional power generation plants. A favourable energy and environmental profile can also be achieved by diesel power systems (DPSs) and biodiesel fuel systems (BFSs), especially if the straw is used for power generation. In particular, the primary energy saving is about 58 per cent for DPSs and 72 per cent for BFSs without any straw energy use and about 67 per cent and 74 per cent with straw energy use, respectively. Moreover, these systems allow a reduction of the greenhouse (by about 55—58 per cent) and acidification impacts (from 21 per cent to 38 per cent), except for the BFS without any straw energy use, which increases the acidification impact by about 42 per cent. The study also demonstrates that crop cultivation greatly affects the performance, owing to the use of fuels and fertilizers.
Chiral Ligand Controlled Helix-sense-selective Atom Transfer Radical Polymerization of 1-Phenyldibenzosuberyl Methacrylate
Authors: Gong Hang , Yang Nian-Fa , Yang Li-Wen , Deng Guo-Jun , Liu Ji , Luo Yong-Feng
Published: May 2011

The atom transfer radical polymerization (ATRP) of 1-phenyldibenzosuberyl methacrylate was carried out using (−)-sparteine (SP) as ligand. The obtained polymers showed high isotacticity, an excess of right- or left-handed helicity, and were optically active. The control of the stereochemistry might be triggered by the fact that the growing species is complexed with chiral metal complexes and thus the monomer insertion during chain propagation is controlled.
Preparation of Porous Cobalt(II) 1,3,5-Benzenetricarboxylates: Product Dependence on the Reaction Solvent and Additive
Authors: Chen Jinxi , Kitagawa Susumu
Published: May 2011

A novel three-dimensional porous coordination polymer, [Co2(HBTC)(BTC)(EtOH)2]·Et3NH·EtOH·6H2O (1) has been synthesized in ethanol at room temperature with 1,4-cyclohexanedicarboxylic acid (1,4-H2CDC) as an additive. The final product of the reaction is found to be dependent upon the solvent and additive employed. When the solvent is changed from ethanol to dimethylformamide, another complex, [Co6(BTC)4(μ-OH2)(DMF)2(H2O)8]·4DMF·5H2O (2) is instead obtained. Without H2CDC, a two-dimensional framework, [Co3(H2BTC)(HBTC)(BTC)(H2O)6]·2H2O (3), is produced in either solvents.
Financial implications and maternal impact of national recommendations for thromboprophylaxis: a retrospective cross-sectional analysis
Authors: Bond Cressida , O'Brien Kate , Draycott Tim , Fox Robert
Published: May 2011

Background

Thromboembolism was a leading direct cause of maternal death in the UK in the last Saving Mothers’ Lives report. National guidance proposes that all women should be risk assessed in pregnancy and after delivery.

Methods

An audit was designed to assess the financial implication for our service. One hundred consecutive live and stillbirths were identified using the maternity database; 97 case records were obtained. Risk factors were identified and individual scores were calculated, together with the proportion that would have extended measures (low-molecular-weight heparin [LMWH], antiembolic stockings).

Results

The series appeared to be representative of the UK pregnant population in terms of age, parity, body mass index, smoking and caesarean rate. Antenatally, 2.1% had a Royal College of Obstetricians and Gynaecologists (RCOG) risk score of three or more and would have been advised to have LMWH throughout pregnancy and the puerperium. Postnatally, 40.1% had an RCOG score of two or more and would have required enoxaparin for one to six weeks. The annual cost of stockings, LMWH and sharps bins approximate to GB£44,847 for every one thousand deliveries, GB£2.6 million for each life saved. About 10% of normal-weight postnatal women who achieved a vaginal birth had a risk score prompting thromboprophylaxis for at least seven days.

Conclusions

These data suggest that the current guidance might represent overmedicalization of pregnancy and that the criteria for thromboprophylaxis should be refined further.
The Mammalian Cone Visual Cycle Promotes Rapid M/L-Cone Pigment Regeneration Independently of the Interphotoreceptor Retinoid-Binding Protein
Authors: Kolesnikov Alexander V. , Tang Peter H. , Parker Ryan O. , Crouch Rosalie K. , Kefalov Vladimir J.
Published: May 2011

Rapid regeneration of the visual pigment following its photoactivation is critical for the function of cone photoreceptors throughout the day. Though the reactions of the visual cycle in the retinal pigment epithelium (RPE) that recycle chromophore for rod pigment regeneration are well characterized, the corresponding mechanisms that enable rapid regeneration of cone pigment are poorly understood. A key remaining question is the relative contribution of the recently discovered cone-specific retina visual cycle and the classic RPE-dependent visual cycle to mammalian cone pigment regeneration. In addition, it is not clear what role, if any, the abundant interphotoreceptor retinoid-binding protein (IRBP) presumed to facilitate the traffic of chromophore, plays in accelerating mammalian cone pigment regeneration. To address these issues, we used transretinal recordings to evaluate M/L-cone pigment regeneration in isolated retinas and eyecups from control and IRBP-deficient mice. Remarkably, the mouse retina promoted M/L-cone dark adaptation eightfold faster than the RPE. However, complete cone recovery required both visual cycles. We conclude that the retina visual cycle is critical for the initial rapid regeneration of mouse M/L-cone pigment during dark adaptation, whereas the slower RPE visual cycle is required to complete the process. While the deletion of IRBP reduced the amplitude and slowed the kinetics of mouse M/L-cone photoresponses, cone adaptation in bright, steady light and the kinetics of cone dark adaptation were not affected in isolated retina or in intact eyecup. Thus, IRBP does not accelerate cone pigment regeneration and is not critical for the function of mouse M/L-cones in bright light.
Visuomotor Coordination Is Different for Different Directions in Three-Dimensional Space
Authors: Tramper Julian J. , Gielen C. C. A. M.
Published: May 2011

In most visuomotor tasks in which subjects have to reach to visual targets or move the hand along a particular trajectory, eye movements have been shown to lead hand movements. Because the dynamics of vergence eye movements is different from that of smooth pursuit and saccades, we have investigated the lead time of gaze relative to the hand for the depth component (vergence) and in the frontal plane (smooth pursuit and saccades) in a tracking task and in a tracing task in which human subjects were instructed to move the finger along a 3D path. For tracking, gaze leads finger position on average by 28 ± 6 ms (mean ± SE) for the components in the frontal plane but lags finger position by 95 ± 39 ms for the depth dimension. For tracing, gaze leads finger position by 151 ± 36 ms for the depth dimension. For the frontal plane, the mean lead time of gaze relative to the hand is 287 ± 13 ms. However, we found that the lead time in the frontal plane was inversely related to the tangential velocity of finger. This inverse relation for movements in the frontal plane could be explained by assuming that gaze leads the finger by a constant distance of ∼2.6 cm (range of 1.5–3.6 cm across subjects).
The CD59 Family Member Leaky/Coiled Is Required for the Establishment of the Blood–Brain Barrier inDrosophila
Authors: Syed Mubarak Hussain , Krudewig Alice , Engelen Daniel , Stork Tobias , Klämbt Christian
Published: May 2011

The blood–brain barrier ofDrosophilais established by the subperineurial glial cells that encase the CNS and PNS. The subperineurial glial cells are thin, highly interdigitated cells with epithelial character. The establishment of extensive septate junctions between these cells is crucial for the prevention of uncontrolled paracellular leakage of ions and solutes from the hemolymph into the nervous system. In the absence of septate junctions, macromolecules such as fluorescently labeled dextran can easily cross the blood–brain barrier. To identify additional components of the blood–brain barrier, we followed a genetic approach and injected Texas-Red-conjugated dextran into the hemolymph of embryos homozygous for chromosomal deficiencies. In this way, we identified the 153-aa-large protein Coiled, a new member of the Ly6 (leukocyte antigen 6) family, as being crucially required for septate junction formation and blood–brain barrier integrity. Incoiledmutants, the normal distribution of septate junction markers such as NeurexinIV, Coracle, or Discs large is disturbed. EM analyses demonstrated that Coiled is required for the formation of septate junctions. We further show that Coiled is expressed by the subsperineurial glial cells in which it is anchored to the cell membrane via a glycosylphosphatidylinositol anchor and mediates adhesive properties. Clonal rescue studies indicate that the presence of Coiled is required symmetrically on both cells engaged in septate junction formation.
Synaptic Characteristics of Dentate Gyrus Axonal Boutons and Their Relationships with Aging, Menopause, and Memory in Female Rhesus Monkeys
Authors: Hara Yuko , Park C. Sehwan , Janssen William G. M. , Punsoni Michael , Rapp Peter R. , Morrison John H.
Published: May 2011

Age-related memory impairment occurs in many mammalian species, including humans. Moreover, women undergoing the menopausal transition often complain of problems with memory. We recently reported that rhesus monkeys display age- and menopause-related recognition memory impairment on a hippocampus-reliant test [delayed nonmatching-to-sample (DNMS)]. In the same monkeys, perforated synapse densities in the dentate gyrus outer molecular layer (OML) correlated with DNMS recognition accuracy, while total axospinous synapse density was similar across age and menses groups. The current study examined whether synaptic characteristics of OML axonal boutons are coupled with age- or menopause-related memory deficits. Using serial section electron microscopy, we measured the frequencies of single-synapse boutons (SSBs), multiple-synapse boutons (MSBs), and boutons with no apparent synaptic contacts [nonsynaptic boutons (NSBs)] in the OML. Aged females had double the percentage of NSBs compared with young females, and this measure correlated positively and inversely with DNMS acquisition (number of trials to criterion) and delay performance (average accuracy), respectively. Aged compared with young females also had a lower frequency of MSBs and a lower number of synaptic contacts per MSB, and the latter variable inversely correlated with DNMS acquisition. Although proportions of NSBs, SSBs, and MSBs were similar across menses groups, compared with premenopausal monkeys, peri/postmenopausal monkeys had fewer MSBs contacting one or more segmented perforated synapses, and the abundance of this bouton subtype positively correlated with DNMS performance. These results suggest that age- and menopause-related shifts in OML synaptic subtypes may be coupled with deficits in task acquisition and recognition memory.
Evidence for Reduced Experience-Dependent Dendritic Spine Plasticity in the Aging Prefrontal Cortex
Authors: Bloss Erik B. , Janssen William G. , Ohm Daniel T. , Yuk Frank J. , Wadsworth Shannon , Saardi Karl M. , McEwen Bruce S. , Morrison John H.
Published: May 2011

Cognitive functions that require the prefrontal cortex are highly sensitive to aging in humans, nonhuman primates, and rodents, although the neurobiological correlates of this vulnerability remain largely unknown. It has been proposed that dendritic spines represent the primary site of structural plasticity in the adult brain, and recent data have supported the hypothesis that aging is associated with alterations of dendritic spine morphology and plasticity in prefrontal cortex. However, no study to date has directly examined whether aging alters the capacity for experience-dependent spine plasticity in aging prefrontal neurons. To address this possibility, we used young, middle-aged, and aged rats in a behavioral stress paradigm known to produce spine remodeling in prefrontal cortical neurons. In young rats, stress resulted in dendritic spine loss and altered patterns of spine morphology; in contrast, spines from middle-aged and aged animals were remarkably stable and did not show evidence of remodeling. The loss of stress-induced spine plasticity observed in aging rats occurred alongside robust age-related reductions in spine density and shifts in remaining spine morphology. Together, the data presented here provide the first evidence that experience-dependent spine plasticity is altered by aging in prefrontal cortex, and support a model in which dendritic spines become progressively less plastic in the aging brain.
Auditory Event-Related Response in Visual Cortex Modulates Subsequent Visual Responses in Humans
Authors: Naue Nicole , Rach Stefan , Strüber Daniel , Huster Rene J. , Zaehle Tino , Körner Ursula , Herrmann Christoph S.
Published: May 2011

Growing evidence from electrophysiological data in animal and human studies suggests that multisensory interaction is not exclusively a higher-order process, but also takes place in primary sensory cortices. Such early multisensory interaction is thought to be mediated by means of phase resetting. The presentation of a stimulus to one sensory modality resets the phase of ongoing oscillations in another modality such that processing in the latter modality is modulated. In humans, evidence for such a mechanism is still sparse. In the current study, the influence of an auditory stimulus on visual processing was investigated by measuring the electroencephalogram (EEG) and behavioral responses of humans to visual, auditory, and audiovisual stimulation with varying stimulus-onset asynchrony (SOA). We observed three distinct oscillatory EEG responses in our data. An initial gamma-band response around 50 Hz was followed by a beta-band response around 25 Hz, and a theta response around 6 Hz. The latter was enhanced in response to cross-modal stimuli as compared to either unimodal stimuli. Interestingly, the beta response to unimodal auditory stimuli was dominant in electrodes over visual areas. The SOA between auditory and visual stimuli—albeit not consciously perceived—had a modulatory impact on the multisensory evoked beta-band responses; i.e., the amplitude depended on SOA in a sinusoidal fashion, suggesting a phase reset. These findings further support the notion that parameters of brain oscillations such as amplitude and phase are essential predictors of subsequent brain responses and might be one of the mechanisms underlying multisensory integration.
Functional Role of Neurotrophin-3 in Synapse Regeneration by Spiral Ganglion Neurons on Inner Hair Cells after Excitotoxic TraumaIn Vitro
Authors: Wang Qiong , Green Steven H.
Published: May 2011

Spiral ganglion neurons (SGNs) are postsynaptic to hair cells and project to the brainstem. The inner hair cell (IHC) to SGN synapse is susceptible to glutamate excitotoxicity and to acoustic trauma, with potentially adverse consequences to long-term SGN survival. We used a cochlear explant culture from P6 rat pups consisting of a portion of organ of Corti maintained intact with the corresponding portion of spiral ganglion to investigate excitotoxic damage to IHC–SGN synapsesin vitro. The normal innervation pattern is preservedin vitro. Brief treatment with NMDA and kainate results in loss of IHC–SGN synapses and degeneration of the distal type 1 SGN peripheral axons, mimicking damage to SGN peripheral axons caused by excitotoxicity or noisein vivo. The number of IHC presynaptic ribbons is not significantly altered. Reinnervation of IHCs occurs and regenerating axons remain restricted to the IHC row. However, the number of postsynaptic densities (PSDs) does not fully recover and not all axons regrow to the IHCs. Addition of either neurotrophin-3 (NT-3) or BDNF increases axon growth and synaptogenesis. Selective blockade of endogenous NT-3 signaling with TrkC–IgG reduced regeneration of axons and PSDs, but TrkB–IgG, which blocks BDNF, has no such effect, indicating that endogenous NT-3 is necessary for SGN axon growth and synaptogenesis. Remarkably, TrkC–IgG reduced axon growth and synaptogenesis even in the presence of BDNF, indicating that endogenous NT-3 has a distinctive role, not mimicked by BDNF, in promoting SGN axon growth in the organ of Corti and synaptogenesis on IHCs.
Nucleus Accumbens Medium Spiny Neurons Target Non-Dopaminergic Neurons in the Ventral Tegmental Area
Authors: Xia Yanfang , Driscoll Joseph R. , Wilbrecht Linda , Margolis Elyssa B. , Fields Howard L. , Hjelmstad Gregory O.
Published: May 2011

The midbrain ventral tegmental area (VTA) projection to the nucleus accumbens (NAc) is implicated in motivation and reinforcement. A significant number of NAc medium spiny neurons (MSNs) project back to the VTA, although the nature of this projection is essentially unknown. For example, do NAc MSNs directly target accumbens-projecting dopamine neurons and do they act via the GABAAor GABABreceptor? To address these issues, we expressed the light-sensitive channel rhodopsin-2 in the rat NAc and made electrophysiological recordings from VTA neuronsex vivo. We found that the NAc directly targets non-dopaminergic VTA neurons, including some that project back to the NAc. These MSN GABAergic terminals are opioid sensitive and act via GABAAreceptors.
Flexible Categorization of Relative Stimulus Strength by the Optic Tectum
Authors: Mysore Shreesh P. , Knudsen Eric I.
Published: May 2011

Categorization is the process by which the brain segregates continuously variable stimuli into discrete groups. We report that patterns of neural population activity in the owl optic tectum (OT) categorize stimuli based on their relative strengths into “strongest” versus “other.” The category boundary shifts adaptively to track changes in the absolute strength of the strongest stimulus. This population-wide categorization is mediated by the responses of a small subset of neurons. Our data constitute the first direct demonstration of explicit categorization of stimuli by a neural network based on relative stimulus strength or salience. The finding of categorization by the population code relaxes constraints on the properties of downstream decoders that might read out the location of the strongest stimulus. These results indicate that the ensemble neural code in the OT could mediate bottom-up stimulus selection for gaze and attention, a form of stimulus categorization in which the category boundary often shifts within hundreds of milliseconds.