bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental regulation of locomotive activity in Xenopus primordial germ cells
Authors: Terayama Kohei , Kataoka Kensuke , Morichika Keisuke , Orii Hidefumi , Watanabe Kenji , Mochii Makoto
Published: December 2012

Primordial germ cells (PGCs) arise in the early embryo and migrate toward the future gonad through species‐specific pathways. They are assumed to change their migration properties dependent on their own genetic program and/or environmental cues, though information concerning the developmental change in PGC motility is limited. First, we re‐examined the distribution of PGCs in the endodermal region of Xenopus embryos at various stages by using an antibody against Xenopus Daz‐like protein, and found four stages of migration, namely clustering, dispersing, directionally migrating and re‐aggregating. Next, we isolated living PGCs at each stage and directly examined their morphology and locomotive activity in cell cultures. PGCs at the clustering stage were round in shape with small blebs and showed little motility. PGCs in both the dispersing and the directionally migrating stages alternated between the locomotive phase with an elongated morphology and the pausing phase with a rugged morphology. The locomotive activity of the elongated PGCs was accompanied by the persistent formation of a large bleb at the leading front. The duration of the locomotive phase was shortened gradually with the transition from the dispersing stage to the directionally migrating stage. At the re‐aggregating stage, PGCs became round in shape and showed no motility. Thus, we directly showed that the locomotive activity of PGCs changes dynamically depending upon the migrating stage. We also showed that the locomotion and blebbing of the PGCs required F‐actin, myosin II activity and RhoA/Rho‐associated protein kinase (ROCK) signaling.
The impact of gender and serum estradiol levels on HDL‐mediated reverse cholesterol transport
Authors: Badeau Robert M. , Metso Jari , Kovanen Petri T. , Lee‐Rueckert Miriam , Tikkanen Matti J. , Jauhiainen Matti
Published: December 2012

Objective

Premenopausal women have a lower incidence of cardiovascular disease compared to men of the same age. Endogenous oestrogens, especially estradiol, presumably protect against atherosclerosis by a variety of mechanisms. Reverse cholesterol transport (RCT) mechanisms also provide protection against this disease. RCT is defined as the removal of cholesterol from peripheral macrophage foam cells, via high‐density lipoproteins (HDL), and cholesterol transportation to the liver for excretion. We have previously shown in a preliminary study that HDL, isolated from premenopausal women, enhanced macrophage cholesterol efflux compared to HDL derived from age‐matched male subjects.

Materials and methods

Here, we expanded this study by analysing a larger population of healthy volunteers and evaluated the capacity of HDL derived from women with high or low serum E2 concentrations, mainly representing premenopausal and postmenopausal women, respectively, or men (each group consisting of 30 subjects) to facilitate cholesterol removal from human THP‐1 macrophages. HDL isolated from serum samples was incubated with [3H] cholesterol oleate‐loaded macrophages for 16 h, after which cholesterol efflux to HDL was determined.

Results

No significant differences in the efflux‐promoting ability of HDL existed among the three groups. Relevant plasma factors involved in further steps of RCT, such as cholesterol ester transfer protein (CETP), phospholipid transfer protein (PLTP) and lecithin:cholesterol acyltransferase (LCAT) activities were also analysed, but no differences were observed among the study groups.

Conclusion

The results do not support a role for estradiol status or gender in modifying the initial step of RCT as a protective mechanism against cardiovascular disease.
The generation of theta rhythm in hippocampal formation maintainedin vitro
Authors: Kowalczyk Tomasz , Bocian Renata , Konopacki Jan
Published: December 2012

The most spectacular example of oscillations and synchrony which appear in the brain is the rhythmic slow activity (theta) of the limbic cortex. Theta rhythm is the best synchronized electroencephalographic activity that can be recorded from the mammalian brain. Hippocampal formation is considered to be the main structure involved in the generation of this activity. Although detailed studies of the physiology and pharmacology of theta‐band oscillations have been carried out since the early 1950s, the first demonstration of atropine‐sensitive theta rhythm, recorded in completely deafferented hippocampal slices of a rat, was performed in the second half of the 1980s. Since the discovery of cholinergically inducedin vitrotheta rhythm recorded from hippocampal formation slices, the central mechanisms underlying theta generation have been successfully studied inin vitroconditions. Most of these experiments were focused on the basic question regarding the similarities between the cholinergically induced theta activity and theta rhythm examinedin vivo. The results of numerousin vitroexperiments strongly suggest that cholinergically induced theta rhythm recorded in hippocampal slices is a useful analogue of theta observed in intact animals, and could be helpful in searching for the mechanisms of oscillations and synchrony in the central nervous system neuronal networks. The objective of the present review is to discuss the main results of experiments concerning theta oscillations recorded inin vitroconditions. It is our intent to provide, on the basis of these results, the characteristics of essential mechanisms underlying the generation of atropine‐sensitivein vitrotheta.
Auditory cortex of the marmoset monkey – complex responses to tones and vocalizations under opiate anaesthesia in core and belt areas
Authors: Rajan Ramesh , Dubaj Vladimir , Reser David H. , Rosa Marcello G. P.
Published: December 2012

Many anaesthetics commonly used in auditory research severely depress cortical responses, particularly in the supragranular layers of the primary auditory cortex and in non‐primary areas. This is particularly true when stimuli other than simple tones are presented. Although awake preparations allow better preservation of the neuronal responses, there is an inherent limitation to this approach whenever the physiological data need to be combined with histological reconstruction or anatomical tracing. Here we tested the efficacy of an opiate‐based anaesthetic regime to study physiological responses in the primary auditory cortex and middle lateral belt area. Adult marmosets were anaesthetized using a combination of sufentanil (8 μg/kg/h, i.v.) and N2O (70%). Unit activity was recorded throughout the cortical layers, in response to auditory stimuli presented binaurally. Stimuli consisted of a battery of tones presented at different intensities, as well as two marmoset calls (‘Tsik’ and ‘Twitter’). In addition to robust monotonic and non‐monotonic responses to tones, we found that the neuronal activity reflected various aspects of the calls, including ‘on’ and ‘off’ components, and temporal fluctuations. Both phasic and tonic activities, as well as excitatory and inhibitory components, were observed. Furthermore, a late component (100–250 ms post‐offset) was apparent. Our results indicate that the sufentanil/N2O combination allows better preservation of response patterns in both the core and belt auditory cortex, in comparison with anaesthetics usually employed in auditory physiology. This anaesthetic regime holds promise in enabling the physiological study of complex auditory responses in acute preparations, combined with detailed anatomical and histological investigation.
Suppression of terpenoid synthesis in plants by a virus promotes its mutualism with vectors
Authors: Luan Jun‐Bo , Yao Dan‐Mei , Zhang Tong , Walling Linda L. , Yang Mei , Wang Yu‐Jun , Liu Shu‐Sheng
Published: December 2012

Vectors often perform better on plants infected with pathogens, and this promotes the spread of pathogens. However, few studies have examined how plant defensive compounds mediate such mutualistic relationships. Although tobacco plants are relatively poor host plants for the whitefly Bemisia tabaci, tobacco's suitability to the whitefly was substantially increased when infected by the begomovirus Tomato yellow leaf curl China virus. The change in suitability was associated with induced terpenoid synthesis in whitefly‐infested plants and repressed terpenoid synthesis in virus‐infected plants. Elevation of terpenoid levels via exogenous stem applications reduced the performance of whiteflies. In contrast, suppression of terpenoid synthesis via gene silencing improved whitefly fitness. By integrating genomics, transcriptomics and metabolomics, this study demonstrated that virus infection depleted the terpenoid‐mediated plant defence against whiteflies, thereby favouring vector–virus mutualism. These data suggest that plant terpenoids play a key role in shaping vector–pathogen relationships.
Soft Post‐Legislative Rulemaking: A Time for More Stringent Control
Authors: Senden Linda
Published: December 2012

The Commission's soft post‐legislative rulemaking by way of communications, notices, codes and similar instruments has become an increasingly important tool for the adequate functioning of the system of shared administration in the EU. However, the development of its legal framework has not kept pace with this, as the Treaty on the EU nor the Treaty on the Functioning of the EU (TFEU) recognise this regulatory phenomenon. As a result, its current procedural control is of a very ad hoc nature. Given the risks this rulemaking involves for the legitimacy of the EU, its practical and legal importance for legal practice and the way in which the Treaty of Lisbon has sought to condition and control the behaviour of the Union institutions, it is argued that the time is ripe for a more stringent and consistent procedural control of soft post‐legislative rulemaking. Some options to realise this are presented for further research.
Impact Assessment of EU Non‐Legislative Rulemaking: The Missing Link in ‘New Comitology’
Authors: Alemanno Alberto , Meuwese Anne
Published: December 2012

Impact assessment (IA) has gone from an innocuous technical tool typically used in the pre‐legislative phase to an instrument at the heart of the European institutional machinery. However—in deviation from its roots as a tool governing delegated rulemaking in the US—most experience with IA in the EU has been gathered in a legislative context. Against the background of the recent evolution of the EU's old ‘comitology’ system into a two‐track system of delegated acts and implementing measures, this contribution discusses in three parts the ‘whys,’ ‘whats’ and ‘hows’ of extending IA to ‘non‐legislative rulemaking.’ It explores various aspects of the rulemaking process that IA—if properly applied—could strengthen: consultation, control and quality.
Can fish really feel pain?
Authors: Rose J D , Arlinghaus R , Cooke S J , Diggles B K , Sawynok W , Stevens E D , Wynne C D L
Published: December 2012

We review studies claiming that fish feel pain and find deficiencies in the methods used for pain identification, particularly for distinguishing unconscious detection of injurious stimuli (nociception) from conscious pain. Results were also frequently misinterpreted and not replicable, so claims that fish feel pain remain unsubstantiated. Comparable problems exist in studies of invertebrates. In contrast, an extensive literature involving surgeries with fishes shows normal feeding and activity immediately or soon after surgery.Cfiber nociceptors, the most prevalent type in mammals and responsible for excruciating pain in humans, are rare in teleosts and absent in elasmobranchs studied to date. A‐delta nociceptors, not yet found in elasmobranchs, but relatively common in teleosts, likely serve rapid, less noxious injury signaling, triggering escape and avoidance responses. Clearly, fishes have survived well without the full range of nociception typical of humans or other mammals, a circumstance according well with the absence of the specialized cortical regions necessary for pain in humans. We evaluate recent claims for consciousness in fishes, but find these claims lack adequate supporting evidence, neurological feasibility, or the likelihood that consciousness would be adaptive. Even if fishes were conscious, it is unwarranted to assume that they possess a human‐like capacity for pain. Overall, the behavioral and neurobiological evidence reviewed shows fish responses to nociceptive stimuli are limited and fishes are unlikely to experience pain.
Variation in DVM behaviour of juvenile and adult pearlside (Maurolicus muelleri) linked to feeding strategies and related predation risk
Authors: Staby Arved , Srisomwong Jantra , Rosland Rune
Published: December 2012

In the Norwegian fjord Masfjorden, different developmental stages of the mesopelagic planktivore Maurolicus muelleri form vertically separate sound scattering layers (SSLs) and in late autumn display different diel vertical migration (DVM) behaviour. Post‐larvae and juvenile fish perform normal crepuscular DVM, whereas the large majority of adults remain at depth throughout the diel period. In this study we examined the stomach contents of juvenile and adult fish caught at different times and depths during a 24‐h period in autumn. The different DVM behaviour of these two SSLs in addition to a shallow layer believed to be composed of post‐larvae is explained with a model for visual foraging in aquatic environments that uses gradients in vertical light intensity and copepod density and size as input variables. Field data revealed that vertically migrating juveniles distributed at a higher ambient light intensity and on average consumed 25 times more copepods than non‐migrating adult fish. The model showed that juveniles experienced a 15 times higher prey encounter rate and a higher level of predation risk than non‐migrating adults, and that the energetic benefits for post larvae and juveniles from prolonged feeding in a nearly constant and brighter environment outweigh the associated predation risk. The model also suggests that the visual detection range of piscivore predators is relatively more limited by the turbid surface water than that of their prey, which provide the post‐larva and juvenile life‐stages of M. muelleri a window of reduced visual predation near the surface.
Niche versus neutrality in structuring the beta diversity of damselfly assemblages
Authors: SIEPIELSKI ADAM M. , MCPEEK MARK A.
Published: December 2012

1. Differences among communities in taxonomic composition – beta diversity – are frequently expected to result from taxon‐specific responses to spatial variation in ecological conditions, through niche partitioning. Such process‐derived patterns are in sharp contrast to arguments from neutral theory, where taxa are ecologically equivalent and beta diversity results primarily from dispersal limitation.

2. Here, we compared beta diversity among assemblages of damselflies (Odonata: Zygoptera), for which previous experiments have shown that niche differences maintain genera within a community, but patterns of relative abundance for species within each genus are shaped primarily by neutral dynamics.

3. Using null‐model and ordination‐based methods, we find that both genera and (in contrast to neutral theory) species assemblage composition vary across the landscape in a deterministic fashion, shaped by environmental and spatial factors.

4. While the observed patterns in species composition conflict with theory, we suggest that this a result of weak ecological filters acting to produce spatial variation in assemblages of ecologically similar species undergoing ecological drift within communities. Such patterns are especially likely in systems of relatively weak dispersers like damselflies.
A climate change‐induced threat to the ecological resilience of a subtropical monsoon evergreen broad‐leaved forest in Southern China
Authors: Zhou Guoyi , Peng Changhui , Li Yuelin , Liu Shizhong , Zhang Qianmei , Tang Xuli , Liu Juxiu , Yan Junhua , Zhang Deqiang , Chu Guowei
Published: December 2012

Recent studies have suggested that tropical forests may not be resilient against climate change in the long term, primarily owing to predicted reductions in rainfall and forest productivity, increased tree mortality, and declining forest biomass carbon sinks. These changes will be caused by drought‐induced water stress and ecosystem disturbances. Several recent studies have reported that climate change has increased tree mortality in temperate and boreal forests, or both mortality and recruitment rates in tropical forests. However, no study has yet examined these changes in the subtropical forests that account for the majority of China's forested land. In this study, we describe how the monsoon evergreen broad‐leaved forest has responded to global warming and drought stress using 32 years of data from forest observation plots. Due to an imbalance in mortality and recruitment, and changes in diameter growth rates between larger and smaller trees and among different functional groups, the average DBH of trees and forest biomass have decreased. Sap flow measurements also showed that larger trees were more stressed than smaller trees by the warming and drying environment. As a result, the monsoon evergreen broad‐leaved forest community is undergoing a transition from a forest dominated by a cohort of fewer and larger individuals to a forest dominated by a cohort of more and smaller individuals, with a different species composition, suggesting that subtropical forests are threatened by their lack of resilience against long‐term climate change.
A high‐resolution bioclimate map of the world: a unifying framework for global biodiversity research and monitoring
Authors: Metzger Marc J. , Bunce Robert G. H. , Jongman Rob H. G. , Sayre Roger , Trabucco Antonio , Zomer Robert
Published: December 2012

Aim

To develop a novel global spatial framework for the integration and analysis of ecological and environmental data.

Location

The global land surface excluding Antarctica.

Methods

A broad set of climate‐related variables were considered for inclusion in a quantitative model, which partitions geographic space into bioclimate regions. Statistical screening produced a subset of relevant bioclimate variables, which were further compacted into fewer independent dimensions using principal components analysis (PCA). An ISODATA clustering routine was then used to classify the principal components into relatively homogeneous environmental strata. The strata were aggregated into global environmental zones based on the attribute distances between strata to provide structure and support a consistent nomenclature.

Results

The global environmental stratification (GEnS) consists of 125 strata, which have been aggregated into 18 global environmental zones. The stratification has a 30 arcsec resolution (equivalent to 0.86 km2 at the equator). Aggregations of the strata were compared with nine existing global, continental and national bioclimate and ecosystem classifications using the Kappa statistic. Values range between 0.54 and 0.72, indicating good agreement in bioclimate and ecosystem patterns between existing maps and the GEnS.

Main conclusions

The GEnS provides a robust spatial analytical framework for the aggregation of local observations, identification of gaps in current monitoring efforts and systematic design of complementary and new monitoring and research. The dataset is available for non‐commercial use through the GEO portal (http://www.geoportal.org).
Default of Systemically Important Financial Intermediaries: Short-term Stability versus Incentive Compatibility?
Authors: Dombret Andreas , Ebner André
Published: December 2012

Financial integration and globalization have acted as a major stimulus in the development of large, internationally operating banks, which not only provide cross-border services but also have a local presence. While these banks are themselves drivers of economic integration, they can pose serious threats to financial stability. Their size, interconnectedness and importance as providers of specific services mean that financial institutions can be too-systemic-to-fail (TSTF). Since the entry and exit of market participants is a crucial feature of well-functioning markets, the absence of any credible possibility of failure leads to serious distortions. This analysis gives an overview of the TSTF problem and discusses the challenges to be faced in establishing credible resolution regimes.
More than a decade of international experience with a pdFVIII/VWF concentrate in immune tolerance
Authors: Santagostino E.
Published: December 2012

Approximately 20–30% of patients with severe haemophilia A develop alloantibodies (‘inhibitors’) to infused FVIII rendering use of such replacement therapy ineffective. Once an inhibitor emerges, immune tolerance induction (ITI) is the standard treatment. ITI involves giving regular doses of FVIII concentrate to eradicate the inhibitor and achieve immunogenic acceptance of administered FVIII. In the early 2000s, a retrospective analysis of inhibitor patients treated at a single centre in Germany indicated that success rates were higher when patients were treated with von Willebrand factor (VWF)‐containing plasma‐derived FVIII (pdFVIII/VWF) concentrate compared with recombinant or non‐VWF‐containing pdFVIII products. Importantly, pdFVIII/VWF as rescue therapy was able to convert 8 of 10 patients who had failed primary ITI with recombinant or non‐VWF‐containing pdFVIII product. A subsequent study from Italy in patients with poor prognostic factors for ITI success also reported good success rates with pdFVIII/VWF as rescue therapy (53% success; 41% partial success).

The Grifols‐Immune Tolerance Induction (G‐ITI) Study represents the largest group of haemophilia A inhibitor patients treated with a single pdFVIII/VWF concentrate (Alphanate®/Fanhdi®) to be reported to date. Data have been collected for 95 patients who underwent primary or rescue ITI at 46 centres in Europe and the US. Currently, published data are available for 33 patients in the US cohort (11 centres), and data from the European cohort are being analysed. Both groups contained patients with poor prognostic factors and most patients received a high‐dose regimen (≥100 IU pdFVIII/VWF kg−1 daily). As expected, the success rate was better for primary vs. rescue ITI and for patients with good vs. poor prognostic factors. However, more than half the patients in the US cohort receiving rescue ITI achieved success (33% complete success; 20% partial success). These results should encourage clinicians to consider the use of pdFVIII/VWF concentrates for rescue ITI. Published outcomes data from the total global G‐ITI cohort (95 patients) are awaited with anticipation.
Management of patients with long‐term inhibitors: is immune tolerance an underestimated life‐long solution?
Authors: Di Minno G. , Coppola A.
Published: December 2012

Immune tolerance induction (ITI) is recognized as the first choice treatment in haemophilic patients with inhibitors, with the aim of restoring safe and effective standard factor VIII replacement and, particularly, prophylaxis in children. For the latter, literature data and clinical practice support the optimal cost utility ratio of ITI. Indeed, the high success rate, the low incidence of inhibitor recurrence after successful ITI and the possibility of preventing joint deterioration, enable one to predict a considerable long‐term reduction of costs in the majority of treated patients. Therefore, in spite of high costs and open issues about optimal regimens, ITI is actually attempted in virtually all children with inhibitors. Few patients with long‐standing inhibitors presently undergo ITI, particularly in the case of severe bleeding tendency. In this setting, uncertainties concerning management are amplified by the paucity of literature data and psychological reluctance by both patients and treaters due to the perceived poor prognosis and the demanding treatment (also in terms of costs). However, clinical data suggest that the role of age at ITI start and of time interval from inhibitor diagnosis, as predictors of ITI outcome, should be considered in a larger framework of proposed and more established prognostic factors. Moreover, optimising ITI management, particularly with respect to inhibitor titre at ITI start and avoidance of adverse events or interruption of treatment, may also contribute to improve outcomes. Although the economic constraints of the present era significantly affect resources for such a high‐cost treatment, the individual cost‐utility ratio (bleeding tendency and risk of fatal bleeding, arthropathy and need for orthopaedic surgery, comorbidities, quality of life) should be assessed carefully to determine whether ITI is a suitable option and thus not preclude adults from the opportunity of inhibitor eradication.
Cannabinoids and Hallucinogens for Headache
Authors: McGeeney Brian E.
Published: December 2012

Hallucinogens and most cannabinoids are classified under schedule 1 of theFederalControlledSubstancesAct 1970, along with heroin and ecstacy. Hence they cannot be prescribed by physicians, and by implication, have no accepted medical use with a high abuse potential. Despite their legal status, hallucinogens and cannabinoids are used by patients for relief of headache, helped by the growing number ofAmerican states that have legalized medical marijuana. Cannabinoids in particular have a long history of use in the abortive and prophylactic treatment of migraine before prohibition and are still used by patients as a migraine abortive in particular. Most practitioners are unaware of the prominence cannabis or “marijuana” once held in medical practice. Hallucinogens are being increasingly used by cluster headache patients outside of physician recommendation mainly to abort a cluster period and maintain quiescence for which there is considerable anecdotal success. The legal status of cannabinoids and hallucinogens has for a long time severely inhibited medical research, and there are still no blinded studies on headache subjects, from which we could assess true efficacy.
Seroepidemiology of Helicobacter pylori Infection in a Mennonite Community in Durango State, Mexico
Authors: Alvarado‐Esquivel Cosme
Published: December 2012

Background

The epidemiology of Helicobacter pylori infection among Mennonites (an ethnic group of German descent living in rural communities in Mexico) has not been previously studied.

Materials and Methods

The prevalence of anti‐H. pylori IgG antibodies was examined in 152 Mennonite individuals in Durango State, Mexico, using enzyme‐linked immunoassays. Seroprevalence association with sociodemographic, clinical, and behavioral characteristics of the Mennonite community was also investigated.

Results

In total, 77 (50.7%) of the 152 Mennonite participants (mean age, 38.4 ± 15.5 years) had H. pylori IgG antibodies, 35 (45.4%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence rates of H. pylori and H. pylori IgG antibody levels. On the other hand, seroprevalence of H. pylori increased significantly with age and was significantly higher among women with history of deliveries and abortions than among those with no such obstetric characteristics. Logistic regression analysis of behavioral characteristics showed that H. pylori infection was associated with a low frequency of eating at restaurants and at fast food outlets (up to 10 times/year) (OR = 2.77; 95% CI: 1.28–5.98; p = .009), and eating meat (up to 3 days/week) (OR = 2.84; 95% CI: 1.36–5.91; p = .005).

Conclusions

This is the first report on the seroprevalence of H. pylori among Mennonites, factors contributing to such infection, and the association of H. pylori infection with abortions and low frequencies of eating out of home and meat. Further research should be conducted on this topic.
Patients' and clinicians' views of comparing the performance of providers of surgery: a qualitative study
Authors: Hildon Zoe , Allwood Dominique , Black Nick
Published: December 2012

Objectives

Comparison of providers' outcomes is intended to encourage patient choice and stimulate clinicians to improve the quality of their services. Given that success will depend on how patients and clinicians respond, our aim was to explore their views of using outcome data to compare providers.

Method

Qualitative data from six focus groups with patients (n = 45) and seven meetings with surgical clinicians (n = 107) were collected during autumn 2010. Discussions audio‐taped, transcribed and a thematic analysis carried out.

Results

Patients and clinicians confirmed the value of making comparisons of the outcomes of providers publicly available. However, both groups harboured three principal concerns: the validity of the data; fears that the data would be misinterpreted by the media, politicians and commissioners, and the focus should not just be on providers but also on the performance of individual surgeons. In addition, patients felt that information on providers' outcomes would only ever have a limited impact on their choice because there were other important factors to be taken into account: accessibility, waiting time, the size of the provider and the quality of other aspects such as cleanliness and nursing. Also patients acknowledged the importance of friends' and relatives' experiences and that they would seek their GP's advice.

Conclusions

While comparisons of providers' outcomes should be available to patients to stimulate improvements in performance, information should be directed principally to hospital clinicians and to GPs. Impact may be enhanced by providing data on individual clinicians rather than providers. The extent to which these findings are generalizable to other areas of health care is uncertain.
Insights from in situ analysis of TCR–pMHC recognition: response of an interaction network
Authors: Zhu Cheng , Jiang Ning , Huang Jun , Zarnitsyna Veronika I. , Evavold Brian D.
Published: December 2012

Recognition of peptide presented by the major histocompatibility complex (pMHC) molecule by the T‐cell receptor (TCR) determines T‐cell selection, development, differentiation, fate, and function. Despite intensive studies on the structures, thermodynamic properties, kinetic rates, and affinities of TCR–pMHC interactions in the past two decades, questions regarding the functional outcome of these interactions, i.e. how binding of the αβ TCR heterodimer with distinct pMHCs triggers different intracellular signals via the adjacent CD3 components to produce different T‐cell responses, remain unclear. Most kinetic measurements have used surface plasmon resonance, a three‐dimensional (3D) technique in which fluid‐phase receptors and ligands are removed from their cellular environment. Recently, several two‐dimensional (2D) techniques have been developed to analyze molecular interactions on live T cells with pMHCs presented by surrogate antigen‐presenting cells or supported planar lipid bilayers. The insights from these in situ analyses have provided a sharp contrast of the 2D network biology approach to the 3D reductionist approach and prompted rethinking of our current views of T‐cell triggering. Based on these insights, we propose a mechanochemical coupled triggering hypothesis to explain why the in situ kinetic parameters differ so much from their 3D counterparts, yet correlate so much better with T‐cell functional responses.
Stromal and hematopoietic cells in secondary lymphoid organs: partners in immunity
Authors: Malhotra Deepali , Fletcher Anne L. , Turley Shannon J.
Published: December 2012

Secondary lymphoid organs (SLOs), including lymph nodes, Peyer's patches, and the spleen, have evolved to bring cells of the immune system together. In these collaborative environments, lymphocytes scan the surfaces of antigen‐presenting cells for cognate antigens, while moving along stromal networks. The cell‐cell interactions between stromal and hematopoietic cells in SLOs are therefore integral to the normal functioning of these tissues. Not only do stromal cells physically construct SLO architecture but they are essential for regulating hematopoietic populations within these domains. Stromal cells interact closely with lymphocytes and dendritic cells, providing scaffolds on which these cells migrate, and recruiting them into niches by secreting chemokines. Within lymph nodes, stromal cell‐ensheathed conduit networks transport small antigens deep into the SLO parenchyma. More recently, stromal cells have been found to induce peripheral CD8+ T‐cell tolerance and control the extent to which newly activated T cells proliferate within lymph nodes. Thus, stromal‐hematopoietic crosstalk has important consequences for regulating immune cell function within SLOs. In addition, stromal cell interactions with hematopoietic cells, other stroma, and the inflammatory milieu have profound effects on key stromal functions. Here, we examine ways in which these interactions within the lymph node environment influence the adaptive immune response.
Individual Voice in Employment Relationships: A Comparison under Different Forms of Workplace Representation
Authors: Marsden David
Published: December 2012

This article considers the role of individual employee voice in regulating the “zone of acceptance” within the employment relationship and examines the extent to which different models of collective voice inhibit or foster the operation of individual voice. It focuses especially on the role of representatives who deal with job‐level grievances and who operate within contrasted frameworks of collective voice. In one, representation is negotiated with the employer, and in the other, it is based on rights established in employment law. The former is commonly associated with shop stewards and unions, and the latter with employee delegates and works councils. It is argued that whereas in the negotiated model, individual and collective voice are substitutes, in the rights‐based one, they are complements. The article also considers how this may alter under dual‐channel representation based on both unions and councils, which is very common in European workplaces. Britain provides an example of the negotiated model and France of both the rights‐based and dual‐channel models. These ideas are tested using data from the 2004 British and French workplace employment relations surveys and confirmed using data from the 1998 surveys.
Keeping the Commitment Model in the Air during Turbulent Times: Employee Involvement at Delta Air Lines
Authors: Kaufman Bruce E.
Published: December 2012

This study provides a four‐decade review and analysis of the commitment model of employment relations at Delta Air Lines and the role played in it by employer‐created structures of employee involvement (EI) and voice. The company has undergone wrenching changes, including deregulation, 9/11, bankruptcy, mergers, and entrance of numerous low‐cost competitors. This study chronicles the resulting ups and downs in the company's fortunes and its efforts to maintain a positive win–win relationship with its employees despite the burden of management missteps, tens of thousands of layoffs, repeated pay and benefit cuts, and merger with conflict‐embittered Northwest Airlines. The fact the company survives today and still has a discernible “spirit of Delta” among employees is not solely or perhaps even principally due to its advanced EI program; on the other hand, without it the company would probably no longer exist.
Not Featherbedding, but Feathering the Nest: Human Resource Management and Investments in Information Technology
Authors: Litwin Adam Seth
Published: December 2012

This study draws on employment relations and management theory, claiming that certain innovative employment practices and work structures pave the way for organizational innovation, namely investments in information technology (IT). It then finds support for the theory in a cross‐section of UK workplaces. The findings suggest that firms slow to adopt IT realize that their conventional employment model hinders their ability to make optimal use of new technologies. Therefore, the paper advances the literature beyond studies of unionization's impact on business investment to a broader set of issues on the employment relations features that make organizations ripe for innovation.
Cloak of compassion, or evidence of elitism? An empirical analysis of white coat ceremonies
Authors: Karnieli‐Miller Orit , Frankel Richard M , Inui Thomas S
Published: December 2012

Context  White coat ceremonies (WCCs) are widely prevalent as a celebration of matriculation in medical schools. Critics have questioned whether these ceremonies can successfully combine the themes of professionalism and humanism, as well as whether the white coat is an appropriate symbol.

Objectives  This study aimed to add a process of empirical assessment to the discussion of these criticisms by analysing the content and messages communicated during these ceremonies.

Methods  Multiple qualitative methods were used to discern the core meanings expressed in a sample of 18 ceremonies through the analysis of artefacts, words, phrases, statements and narratives. Out of a stratified random sample of 25 US schools of medicine conducting WCCs in 2009, 18 schools submitted video, audio and written materials.

Results  All ceremonies followed the same general format, but varied in their content, messages and context. Ceremonies included five principal descriptions of what is symbolised by the white coat, including: commitment to humanistic professional care; a reminder of obligations and privileges; power; the student’s need to ‘grow’, and the white coat as a mantle. Statements about obligations were made three times more frequently than statements about privileges. Key words or phrases in WCCs mapped to four domains: professionalism; morality; humanism, and spirituality. Spoken narratives focused on humility and generosity.

Conclusions  The WCCs studied did not celebrate the status of an elite class, but marked the beginning of educational, personal and professional formation processes and urged matriculants to develop into doctors ‘worthy of trust’. The ceremonies centred on the persons entering the vocation, who were invited to affirm its calling and obligations by donning a symbolic garb, and to join an ancient and modern tradition of healing and immersion in their community. The schools’ articulated construct of the white coat situated it as a symbol of humanism. This study’s findings may clarify and guide schools’ choices in designing their own WCCs.
Low temperatures counteract short‐day induced nitrogen storage, but not accumulation of bark storage protein transcripts in bark of grey poplar (Populus × canescens) trees
Authors: Wildhagen H. , Bilela S. , Rennenberg H.
Published: December 2012

According to climate change scenarios, the seasonal course of temperature will change in most regions of the world, raising the question of how this will influence seasonal nitrogen (N) storage in deciduous trees. The key to this question is a detailed understanding of the underlying regulatory mechanisms, which was addressed in this study by analysing (i) the effects of low temperatures (13–1 °C) on bark storage protein (BSP) transcription, BSP and total protein accumulation and amino acid metabolism; (ii) the effects of interactions between low temperatures and photoperiod on these processes; and (iii) the regulatory role of amino acids in the bark. For this purpose, we exposed grey poplar trees (Populus × canescens) to three different treatments of changing photoperiod at constant temperature, changing temperature at constant photoperiod, and both changing photoperiod and temperature. Under a shortened photoperiod, a substantial increase of BSP transcripts was observed that was correlated with the accumulation of bark proteins, indicating a metabolic shift to promote long‐term N storage. Irrespective of the applied photoperiod, exposure to low temperatures (5 or 1 °C) caused a strong increase of BSP transcripts, which was not paralled by significant increases of BSP and total bark proteins. We conclude that the interaction between effects of photoperiod and temperature is dependent on the carbon status of the trees, and reflects a metabolic adjustment of reduced carbon consumption for BSP synthesis. These results demonstrate the differential temperature sensitivity of processes involved in seasonal N storage, implying vulnerability to changing environmental conditions.
Inter‐ and intra‐specific variability in isoprene production and photosynthesis of Central European oak species
Authors: Steinbrecher R. , Contran N. , Gugerli F. , Schnitzler J.‐P. , Zimmer I. , Menard T. , Günthardt‐Goerg M.S.
Published: December 2012

European deciduous oaks are closely related and are known for their strong emission of volatile isoprenoids. They are chemo‐taxonomically diverse, but hybridise frequently. Four‐year‐old oak seedlings growing together in a model ecosystem facility under near‐natural conditions were studied. The leaves were morphologically classified in the three oak species Quercus robur, Q. pubescens and Q. petraea (with four provenances each) and further investigated by a molecular‐genetic approach. Q. robur was morphologically and genetically clearly different from Q. pubescens and Q. petraea, whereas Q. pubescens and Q. petraea individuals used in this study were morphologically and genetically more similar. There was a minor impact of among and within species variability on isoprene synthesis, isoprene emission and photosynthesis. Isoprene emission rates normalised to 25 °C leaf temperature ranged from 5.78 to 10.66 nmol m−2 s−1, whereas photosynthesis ranged from 12.8 to 17.6 μmol m−2 s−1. On cloudy days, among the provenances of each species, only net photosynthesis of the Q. robur provenance Hünenberg was reduced and isoprene synthase activity of the Q. pubescens provenance Promotogno increased. On sunny days, photosynthesis did not differ among the provenances. Over all provenances, gas exchange on cloudy days did not differ significantly from sunny days. In the combined data of cloudy and sunny days, no differences between the studied provenances and oak species were detected in isoprene emission and photosynthesis. Thus, isoprene emission and photosynthesis rates were remarkably stable among oak species and provenances. The results indicate that taxonomic differences in the studied oak species are not reflected in isoprene emission and photosynthesis, probably because of the high plasticity of gene expression resulting in high phenotypic flexibility.
Mirtazapine protects against cisplatin‐induced oxidative stress and DNA damage in the rat brain
Authors: Gulec Mustafa , Oral Elif , Dursun Onur B. , Yucel Atakan , Hacimuftuoglu Ahmet , Akcay Fatih , Suleyman Halis
Published: December 2012

Aim

Cisplatin chemotherapy is associated with neurotoxicity, and oxidative stress might play an important role in the pathogenesis. Mirtazapine may be a preventative agent via its less‐known antioxidant properties. The aim of this study was to examine the potential chemoprotective effects of mirtazapine against cisplatin‐induced oxidative stress and DNA damage.

Methods

Twenty‐four rats were divided equally into four groups: control; cisplatin (10 mg/kg i.p.); cisplatin plus mirtazapine (10–30 mg/kg, respectively i.p and p.o.); and mirtazapine (30 mg/kg p.o.). The rats were killed at the end of the 14th day of treatment. Brain tissue was examined with regard to antioxidant/oxidant biochemical parameters.

Results

Although glutathione (tGSH) and nitric oxide (NO) end product mean scores were found to be statistically higher in the control group when compared with the cisplatin group (72.44% and 61.99% percentage change [PC], respectively), malondialdehyde (MDA), myeloperoxidase (MPO), and 8‐hydroxyguanine (8‐OH‐GUA) mean scores were statistically lower in the control group in comparison with the cisplatin group (−55.48%, −67.99%, and −48.81% PC, respectively; P < 0.01). Finally, tGSH and NO end product levels were restored to normal (85.90% and 55.30% PC, respectively), and MDA, MPO, and 8‐OH‐GUA were significantly reduced by treatment with mirtazapine (−60.50%, −78.59%, and −38.10% PC, respectively; P < 0.01).

Conclusion

Mirtazapine has chemoprotective effects against cisplatin‐induced oxidative stress and DNA damage in the rat brain, which may be attributed to its antioxidant capabilities. It would be useful to investigate whether cisplatin at the desired doses can be given concurrently with mirtazapine.
Thoracic computed tomography in absent pulmonary valve syndrome management
Authors: Vincenti Marie , Jacquot Aurélien , Guillaumont Sophie , Milési Christophe , Saguintaah Magali , Pidoux Odile , Kreitmann Bernard , Rideau Aline , Cambonie Gilles
Published: December 2012

A neonate with absent pulmonary valve syndrome (APVS) and features of tetralogy of Fallot presented respiratory distress. The prolonged need for mechanical ventilation was an indication for surgical repair. Preoperative thoracic CT imaging showed nearly complete closure of the distal trachea, compressed by the aneurysmal dilatation of the pulmonary arteries, and its reopening after ventilator pressure was increased. Management of APVS may require high‐pressure ventilation to prevent bronchial collapse due to compression by the pulmonary arteries. In this context, thoracic CT imaging is very useful for adjusting ventilation support so that surgical repair can be performed in optimal conditions.
Child‐onset systemic sclerosis positive for anticentromere antibodies: Two Japanese cases
Authors: Inamo Yasuji
Published: December 2012

Systemic sclerosis (SSc) is an uncommon connective tissue disease of childhood. Moreover, pediatric SSc positive for anticentromere antibodies (ACA) is extremely rare. We describe two cases of ACA‐positive SSc in Japanese girls with clinical findings. Case 1 is a 15‐year‐old female. From disease onset at 7 years, she developed limited cutaneous (no internal involvement) SSc positive for ACA and anti‐U1RNP antibodies, but negative for antitopoisomerase I antibodies (ATA). She also showed calcinosis, sclerodactyly, and telangiectasia, but not Raynaud's phenomenon. Case 2 is also a 15‐year‐old female with onset at the same age. Her diagnosis was limited cutaneous SSc positive for ACA, anti‐SSA/Ro antibodies, and anti‐thyroid antibodies, but not ATA. She showed sclerodactyly, telangiectasia, and Raynaud phenomenon, as well as complicated Sjögren's syndrome and chronic thyroiditis with euthyroidism. We reported that two Japanese girls with SSc were positive for ACA and other antibodies with the exception of ATA.
Completely infarcted smooth muscle tumor of the placental membrane
Authors: Haltas Hacer , Bayrak Reyhan , Yenidunya Sibel , Tevrizci Hatice
Published: December 2012

Non‐trophoblastic tumor of the placenta is rare, and so is placental smooth muscle tumor. We report leiomyoma of the placental membrane, which was discovered on cesarean section. Histologically, the tumor was a benign leiomyoma with complete necrosis, and this finding was confirmed immunohistochemically. Only six cases of smooth muscle tumors of the placenta have been reported to date. This is the third report of leiomyoma involving the placental membrane.