Dynamics of natural populations of the dertitivorous mudsnail Potamopyrgus antipodarum (Gray) (Hydrobiidae) in two interconnected Lakes differing in trophic state

Here we investigate the allocation of resources between growth and reproduction by surveying the dynamics of natural populations of the aquatic detritivorous mudsnail Potamopyrgus antipodarum from two interconnected lakes that differ in trophic state. The size distributions and reproductive output of the snail populations was analyzed monthly by field surveys spanning 3 years, and in a controlled microcosm experiment to evaluate the reproductive potential under laboratory conditions. Snails in the meso-oligotrophic lake showed reduced growth and a smaller size compared to snails in the eutrophic lake. However, the numbers of eggs and nearly-neonates per adult snail did not differ significantly between the two populations. It is speculated that P. antipodarum populations living under meso-oligotrophic conditions may consistently invest more internal energy in reproduction at the expense of growth and that food quantity may be an important driver for macro-invertebrate resource allocation in detrital food webs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-3-736) contains supplementary material, which is available to authorized users

Possible lack of full cross-resistance of 5HT3 antagonists; a pilot study

We investigated the potential of cross-over to the serotonin receptor (5HT3) antagonist ondansetron after protection failure with tropisetron. Several cases of complete protection were observed. These limited data suggest that there is an indication for retreatment with a different 5HT3 antagonist after an initial failure to another and also stress the need and relevance for comparative studies between 5HT3 antagonists

Haemovigilance:current practices and future developments

Haemovigilance is the systematic surveillance of adverse events in the transfusion chain, and encompasses activities that contribute to the safety and quality in the process of blood donation and transfusion. From the start in the early 1990s, haemovigilance has put emphasis on different adverse reactions and incidents in recipients and subsequently in donors, pointing to vulnerabilities in the transfusion chain and areas for prevention. More recently, the monitoring of efficacy and efficiency of transfusion practice has been introduced in the concept of haemovigilance. The purpose of this review is to present an overview of the current status and future developments of haemovigilance. Haemovigilance is part of the quality systems of the blood collection establishments, transfusion laboratories and the transfusion institutions. The monitoring, investigation and analysis of adverse events generates relevant data for the quality cycle of these systems, driving continuous improvement in transfusion practice. Recommendations based on haemovigilance findings have led to changes in clinical guidelines and policies. Despite the progress haemovigilance has made, further developments are needed. Current challenges lie in the field of the establishment of haemovigilance systems in low resource settings, the international harmonisation of definitions and the prevention of underreporting. In addition, the causal relationship between the transfusion and the reaction is often unclear. Biomarkers may aid in the imputability assessment and their role in the diagnosis of transfusion reactions needs to be further investigated. Future developments are expected in automated reporting, the use of big data and increased shareability of international data, contributing to a better understanding of the causal mechanisms and risk factors, and to prevention of adverse events. Haemovigilance is an evolving discipline and will continue to contribute to improving the safety of blood donation and transfusion

Exposure to TARC alters beta2-adrenergic receptor signaling in human peripheral blood T lymphocytes

The beta(2)-adrenergic receptor (beta(2)-AR) negatively regulates T cell activity through the activation of the G(s)/adenylyl cyclase/cAMP pathway. beta(2)-AR desensitization, which can be induced by its phosphorylation, may have important consequences for the regulation of T cell function in asthma. In the present study we demonstrate that the C-C chemokine thymus and activation-regulated chemokine (TARC) impairs the ability of beta(2)-agonist fenoterol to activate the cAMP downstream effector cAMP-responsive element binding protein (CREB) in freshly isolated human T cells. The TARC-induced activation of Src kinases resulted in membrane translocation of both G protein-coupled receptor kinase (GRK) 2 and beta-arrestin. Moreover, TARC was able to induce Src-dependent serine phosphorylation of the beta(2)-AR as well as its association with GRK2 and beta-arrestin. Finally, in contrast to CREB, phosphorylation of Src and extracellular signal-regulated kinase was enhanced by fenoterol upon TARC pretreatment. In summary, we show for the first time that TARC exposure impairs beta(2)-AR function in T cells. Our data suggest that this is mediated by Src-dependent activation of GRK2, resulting in receptor phosphorylation, binding to beta-arrestin, and a switch from cAMP-dependent signaling to activation of the MAPK pathway. We propose that aberrant T cell control in the presence of endogenous beta-agonists promotes T cell-mediated inflammation in asthma

Application of Circular Dichroism Spectroscopy in the Study of Mixed-Valence Asymmetric Ruthenium Polypyridyl Complexes

Circular dichroism (CD) spectroelectrochemistry is used to determine the extent of singly occupied molecular orbital delocalization in mixed-valence multinuclear complexes, specifically the mixed-valence RuIIRuIII states of the four diastereoisomers of [(Ru(bpy)2)2(bpt)]3+ [bpy = 2,2'-bipyridyl and bpt = 3,5-bis(pyrid-2'-yl)-1,2,4-triazolato anion]. The complex was found to be stable to thermal racemization in the three oxidation states, but photoracemization in the RuIIRuII state was observed.

Pregnancy Outcomes:Effects of Metformin (POEM) study: a protocol for a long-term, multicentre, open-label, randomised controlled trial in gestational diabetes mellitus

INTRODUCTION: Gestational diabetes mellitus (GDM) is a common disorder of pregnancy with health risks for mother and child during pregnancy, delivery and further lifetime, possibly leading to type 2 diabetes mellitus (T2DM). Current treatment is focused on reducing hyperglycaemia, by dietary and lifestyle intervention and, if glycaemic targets are not reached, insulin. Metformin is an oral blood glucose lowering drug and considered safe during pregnancy. It improves insulin sensitivity and has shown advantages, specifically regarding pregnancy-related outcomes and patient satisfaction, compared with insulin therapy. However, the role of metformin in addition to usual care is inconclusive and long-term outcome of metformin exposure in utero are lacking. The primary aim of this study is to investigate the early addition of metformin on pregnancy and long-term outcomes in GDM. METHODS AND ANALYSIS: The Pregnancy Outcomes: Effects of Metformin study is a multicentre, open-label, randomised, controlled trial. Participants include women with GDM, between 16 and 32 weeks of gestation, who are randomised to either usual care or metformin added to usual care, with insulin rescue in both groups. Metformin is given up to 1 year after delivery. The study consists of three phases (A-C): A-until 6 weeks after delivery; B-until 1 year after delivery; C-observational study until 20 years after delivery. During phase A, the primary outcome is a composite score consisting of: (1) pregnancy-related hypertension, (2) large for gestational age neonate, (3) preterm delivery, (4) instrumental delivery, (5) caesarean delivery, (6) birth trauma, (7) neonatal hypoglycaemia, (8) neonatal intensive care admission. During phase B and C the primary outcome is the incidence of T2DM and (weight) development in mother and child. ETHICS AND DISSEMINATION: The study was approved by the Central Committee on Research Involving Human Subjects in the Netherlands. Results will be submitted for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02947503

Reciprocal Associations between Parenting Challenges and Parents' Personality Development in Young and Middle Adulthood

Having children affects many aspects of people's lives. However, it remains unclear to what degree the challenges that come along with having children are associated with parents' personality development. We addressed this question in two studies by investigating the relationship between parenting challenges and personality development in mothers of newborns (Study 1, N = 556) and the reciprocal associations between (mastering) parenting challenges and personality development in parents of adolescents (Study 2, N = 548 mothers and 460 fathers). In Study 1, we found the stress of having a newborn baby to be associated with declines in maternal Agreeableness, Conscientiousness, and Emotional Stability. Parenting challenges were also related to personality development in parents of adolescent children in Study 2, with parent–child conflict being reciprocally associated with decreases in Conscientiousness and Emotional Stability. Mastering parenting challenges in the form of high parenting self-efficacy, on the other hand, was found to be associated with increases in Agreeableness, Conscientiousness, and Emotional Stability, and vice versa. In sum, our results suggest that mastering the challenges associated with the social role of parenthood is one of the mechanisms underlying personality development in young and middle adulthood

Coordination of Axial Trunk Rotations During Gait in Low Back Pain. A Narrative Review

Chronic low back pain patients have been observed to show a reduced shift of thorax-pelvis relative phase towards out-of-phase movement with increasing speed compared to healthy controls. Here, we review the literature on this phase shift in patients with low back pain and we analyze the results presented in literature in view of the theoretical motivations to assess this phenomenon. Initially, based on the dynamical systems approach to movement coordination, the shift in thorax-pelvis relative phase with speed was studied as a self-organizing transition. However, the phase shift is gradual, which does not match a self-organizing transition. Subsequent emphasis in the literature therefore shifted to a motivation based on biomechanics. The change in relative phase with low back pain was specifically linked to expected changes in trunk stiffness due to ‘guarded behavior’. We found that thorax-pelvis relative phase is affected by several interacting factors, including active drive of thorax rotation through trunk muscle activity, stride frequency and the magnitude of pelvis rotations. Large pelvis rotations and high stride frequency observed in low back pain patients may contribute to the difference between patients and controls. This makes thorax-pelvis relative phase a poor proxy of trunk stiffness. In conclusion, thorax-pelvis relative phase cannot be considered as a collective variable reflecting the orderly behaviour of a complex underlying system, nor is it a marker of specific changes in trunk biomechanics. The fact that it is affected by multiple factors may explain the considerable between-subject variance of this measure in low back pain patients and healthy controls alike

Evaluating the perceived added value of a threefold intervention to improve palliative care for persons experiencing homelessness:A mixed-method study among social service and palliative care professionals

BACKGROUND: Palliative care for persons experiencing homelessness who reside in social service facilities is often late or lacking. A threefold intervention was implemented to improve palliative care for this population by increasing knowledge and collaboration between social service and palliative care professionals. This consultation service comprised: 1) consultations between social service professionals and palliative care professionals; 2) multidisciplinary meetings involving these professionals; and 3) training of these professionals. This study aims to evaluate the perceived added value of this threefold consultation service in three regions in the Netherlands. METHODS: A mixed-methods evaluation study using structured questionnaires for consultants, requesting consultants, and attendees of multidisciplinary meetings, semi-structured group and individual interviews with social service and palliative care professionals involved, weekly diaries filled out by consultants, and an implementation diary. Qualitative data were analyzed following the principles of thematic analysis. Quantitative data were analyzed descriptively. RESULTS: Thirty-four consultations, 22 multidisciplinary meetings and 9 training sessions were studied during the implementation period of 21 months. Social service professionals made up the majority of all professionals reached by the intervention. In all regions the intervention was perceived to have added value for collaboration and networks of social service and palliative care professionals (connecting disciplines reciprocally and strengthening collaborations), the competences of especially social service professionals involved (competency in palliative care provision, feeling emotionally supported in complex situations), and the quality and timing of palliative care (more focus on quality of life and dying, advance care planning and looking ahead, and greater awareness of death and palliative care). CONCLUSIONS: The threefold consultation service particularly helps social service professionals connect with palliative care professionals. It helps them to identify palliative care needs in good time and to provide qualitatively better palliative care to persons experiencing homelessness

Characterization of Tryptophanase from Vibrio cholerae O1

AbstractTryptophanase (Trpase) encoded by the tnaA gene catalyzes the conversion of tryptophan to indole, which is an extracellular signaling molecule detected in various bacteria including Vibrio cholerae. Indole has been demonstrated to regulate biofilm formation, drug resistance, plasmid maintenance and spore formation of bacteria. In the present study, the tnaA gene from V. cholerae O1 (VcTrpase) was cloned and expressed in E. coli BL21(DE3) tn5:tnaA (a Trpase-deficient competent). VcTrpase was purified by Ni2+-NTA chromatography. The obtained VcTrpase had a molecular mass of approximately 49 kDa, a specific activity of 3 U/mg protein, and absorption peaks at 330 and 435nm. Using a site-directed mutagenesis technique, replacement of Arg419 by Val resulted in a VcTrpase completely devoid of activity. Thus, this site can be a target for drug design for controlling V. cholerae