Analysis of pH variation of various calcium hydroxide compounds in vitro

Among the reasons for the use of calcium hydroxide products, there is their alkalinity. Variations in the alkalinity of six commonly used calcium hydroxide compounds were studied in vitro at different time intervals. All these compounds rendered the saline solution strongly alkaline. Dycal®, Life®, Nucap® and Reocap®, had a weaker effect as compared with Contrasil® and to Pulpdent® paste. Such differences in the pH values were accompanied by differences in calcium loss, as revealed by scanning electron microscopy. Differences in the alkaline pH values and calcium losses among these calcium hydroxide compounds may account for their different clinical effectiveness in vivo.Une des raisons de l’utilisation des produits à base d’hydroxyde de calcium est leur alcalinité. Les variations alcalines des 6 matériaux à base d’hydroxyde de calcium couramment utilisés ont été testées in vitro à différents intervalles de temps. Dycal®, Life®, Nucap® and Reocap®, avaient un effet plus faible que Contrasil® et Pulpdent® paste. Les différences de valeurs de pH étaient accompagnées de pertes de calcium. Les différentes valeurs de pH ainsi que les pertes de calcium pourraient expliquer leur diverse efficacité in vivo

Associations between coronal mass ejections and interplanetary shocks

Nearly continuous complementary coronal observations and interplanetary plasma measurements for the years 1979-1982 are compared. It is shown that almost all low latitude high speed coronal mass ejections (CME's) were associated with shocks at HELIOS 1. Some suitably directed low speed CME's were clearly associated with shocks while others may have been associated with disturbed plasma (such as NCDE's) without shocks. A few opposite hemisphere CME's associated with great flares seem to be associated with shocks at HELIOS

Positive Modulation of ␣-Amino-3-hydroxy-5-methyl-4- isoxazole Propionic Acid (AMPA) Receptors in Prefrontal Cortical Pyramidal Neurons by a Novel Allosteric Potentiator

ABSTRACT Positive modulators of glutamate ␣-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors can enhance cognitive function in several species. The present experiments compared the actions of a novel biarylpropylsulfonamide compound, LY404187, with the prototypical benzoylpiperidine, 1-(quinoxalin-6-ylcarbonyl)-piperidine (CX516), on AMPA receptors of prefrontal cortex (PFC) pyramidal neurons. LY404187 (0.03-10 M) selectively enhanced glutamateevoked currents through AMPA receptor/channels of acutely isolated pyramidal neurons with considerably greater potency (EC 50 ϭ 1.3 Ϯ 0.3 M) and efficacy (E max ϭ 45.3 Ϯ 8.0-fold increase) than did CX516 (EC 50 ϭ 2.8 Ϯ 0.9 mM; E max ϭ 4.8 Ϯ 1.4-fold increase). Both LY404187 and CX516 increased the potency of the glutamate concentration-response profile by 6-and 3-fold, respectively. Rapid perfusion experiments demonstrated that LY404187 produced a marked suppression in the magnitude but no change in the kinetics of receptor desensitization; whereas CX516 produced little change in the degree and a modest deceleration of the desensitization process. In PFC slices, both spontaneous and stimulus-evoked AMPA receptor-mediated excitatory postsynaptic potentials were enhanced by nanomolar concentrations of LY404187. Voltagesensitive N-methyl-D-aspartate (NMDA) receptor-dependent synaptic responses also were indirectly augmented as a consequence of greater postsynaptic depolarization. Consistent with the in vitro data, LY404187 was 1000-fold more potent than CX516 in enhancing the probability of discharge of PFC neurons in response to stimulation of glutamatergic afferents from hippocampus in vivo. This potentiation by LY404187 was reduced by both selective AMPA (LY300168, 1 mg/kg, i.v.) and NMDA (LY235959, 5 mg/kg, i.v.) receptor antagonists. Collectively, these results demonstrate that LY404187 is an extremely potent and centrally active potentiator of native AMPA receptors and has a unique mechanism of action. The therapeutic implications of AMPA receptor potentiators are discussed

How is female mate choice affected by male competition?

Author Posting. © Cambridge Philosophical Society, 2005. This article is posted here by permission of Cambridge Philosophical Society for personal use, not for redistribution. The definitive version was published in Biological Reviews 80: (2005) 559-571, doi:10.1017/S1464793105006809.The plethora of studies devoted to the topics of male competition and female mate choice belie the fact that their interaction remains poorly understood. Indeed, on the question of whether competition should help or hinder the choice process, opinions scattered throughout the sexual selection literature seem unnecessarily polarised. We argue, in the light of recent theoretical and empirical advances, that the effect of competition on mate choice depends on whether it results in the choosy sex attaining high breeding value for total fitness, considering both direct and indirect fitness benefits. Specifically, trade-offs may occur between different fitness benefits if some are correlated with male competitive ability whilst others are not. Moreover, the costs and benefits of mating with competitive males may vary in time and/or space. These considerations highlight the importance of injecting a life-history perspective into sexual selection studies. Within this context, we turn to the sexual selection literature to try to offer insights into the circumstances when competition might be expected to have positive or negative implications for pre-copulatory female choice. In this regard, we elaborate on three stages where competition might impact upon the choice process: (i) during mate detection, (ii) mate evaluation, and (iii) in dictating actual mating outcomes. We conclude by offering researchers several potentially rewarding avenues for future research.This study was supported by an Australian Postgraduate Award, a Sir Keith Murdoch Fellowship, and a Centre for International Mobility Fellowship (to B.B.M.W) and the Academy of Finland (to U.C.)

Examining the effectiveness of general practitioner and nurse promotion of electronic cigarettes versus standard care for smoking reduction and abstinence in hardcore smokers with smoking-related chronic disease:protocol for a randomised controlled trial

BACKGROUND: Despite the clear harm associated with smoking tobacco, many people with smoking-related chronic diseases or serious mental illnesses (SMI) are unwilling or unable to stop smoking. In many cases, these smokers have tried and exhausted all methods to stop smoking and yet clinicians are repeatedly mandated to offer them during routine consultations. Providing nicotine through electronic cigarettes (e-cigarettes) may reduce the adverse health consequences associated with tobacco smoking, but these are not currently offered. The aim of this study is to examine the feasibility, acceptability and effectiveness of general practitioners (GPs) and nurses delivering a brief advice intervention on e-cigarettes and offering an e-cigarette starter pack and patient support resources compared with standard care in smokers with smoking-related chronic diseases or SMI who are unwilling to stop smoking. METHODS/DESIGN: This is an individually randomised, blinded, two-arm trial. Smokers with a smoking-related chronic condition or SMI with no intention of stopping smoking will be recruited through primary care registers. Eligible participants will be randomised to one of two groups if they decline standard care for stopping smoking: a control group who will receive no additional support beyond standard care; or an intervention group who will receive GP or nurse-led brief advice about e-cigarettes, an e-cigarette starter pack with accompanying practical support booklet, and telephone support from experienced vapers and online video tutorials. The primary outcome measures will be smoking reduction, measured through changes in cigarettes per day and 7-day point-prevalence abstinence at 2 months. Secondary outcomes include smoking reduction, 7-day point-prevalence abstinence and prolonged abstinence at 8 months. Other outcomes include patient recruitment and follow-up, patient uptake and use of e-cigarettes, nicotine intake, contamination of randomisation and practitioner adherence to the delivery of the intervention. Qualitative interviews will be conducted in a subsample of practitioners, patients and the vape team to garner their reactions to the programme. DISCUSSION: This is the first randomised controlled trial to investigate whether e-cigarette provision alongside a brief intervention delivered by practitioners leads to reduced smoking and abstinence among smokers with smoking-related chronic diseases or SMI. TRIAL REGISTRATION: ISRCTN registry, ISRCTN59404712. Registered 28/11/17

Caveolin contributes to the modulation of basal and β-adrenoceptor stimulated function of the adult rat ventricular myocyte by simvastatin: A novel pleiotropic effect

The number of people taking statins is increasing across the globe, highlighting the Importance of fully understanding statins effects on the cardiovascular system. The beneficial impact of statins extends well beyond regression of atherosclerosis to include direct effects on tissues of the cardiovascular system (pleiotropic effects). Pleiotropic effects on the cardiac myocyte are often overlooked. Here we consider the contribution of the caveolin protein, whose expression and cellular distribution is dependent on cholesterol, to statin effects on the cardiac myocyte. Caveolin is a structural and regulatory component of caveolae, and is a key regulator of cardiac contractile function and adrenergic responsiveness. We employed an experimental model in which inhibition of myocyte HMG CoA reductase could be studied in the absence of paracrine influences from non-myocyte cells. Adult rat ventricular myocytes were treated with 10 μM simvastatin for 2 days. Simvastatin treatment reduced myocyte cholesterol, caveolin 3 and caveolar density. Negative inotropic and positive lusitropic effects (with corresponding changes in [Ca2]¡) were seen in statin-treated cells. Simvastatin significantly potentiated the inotropic response to β2-, but not β1-, adrenoceptor stimulation. Under conditions of β2-adrenoceptor stimulation, phosphorylation of phospholamban at Ser16and troponin I at Ser23/24was enhanced with statin treatment. Simvastatin increased NO production without significant effects on eNOS expression or phosphorylation (Ser1177), consistent with the reduced expression of caveolin 3, its constitutive Inhibitor. In conclusion, statin treatment can reduce caveolin 3 expression, with functional consequences consistent with the known role of caveolae in the cardiac cell. These data are likely to be of significance, particularly during the early phases of statin treatment, and in patients with heart failure who have altered ß-adrenoceptor signalling. In addition, as caveolin is ubiquitously expressed and has myriad tissue-specific functions, the impact of statin-dependent changes in caveolin is likely to have many other functional sequelae

The 5x1 DAFNE Study Protocol: A cluster randomised trial comparing a standard 5 day DAFNE course delivered over 1 week against DAFNE training delivered over 1 day a week for 5 consecutive weeks.

Background Structured education programmes are now established as an essential component to assist effective self-management of diabetes. In the case of Type 1 diabetes, the Dose Adjustment For Normal Eating (DAFNE) programme improves both glycaemic control and quality of life. Traditionally delivered over five consecutive days, this format has been cited as a barrier to participation by some patients, such as those who work full-time. Some centres in the UK have organised structured education programmes to be delivered one day a week over several consecutive weeks. This type of format may add benefit by allowing more time in which to practice skills between sessions, but may suffer as a result of weaker peer support being generated compared to that formed over five consecutive days. Methods/design We aim to compare DAFNE delivered over five consecutive days (1 week course) with DAFNE delivered one day a week over five weeks (5 week course) in a randomised controlled trial. A total of 213 patients were randomised to attend either a 1 week or a 5 week course delivered in seven participating centres. Study outcomes (measured at baseline, 6 and 12 months post-course) include HbA1c, weight, self-reported rates of severe hypoglycaemia, psychosocial measures of quality of life, and cost-effectiveness. Generalisability was optimised by recruiting patients from DAFNE waiting lists at each centre, and by mailing eligible patients from hospital clinic lists. The inclusion and exclusion criteria were identical to those used to recruit to a standard DAFNE course (e.g., HbA1c <12%, with no lower limit). Qualitative interviews were undertaken with a sub-sample of n=30 patients and their course educators (n=11) to help understand and interpret differences and similarities in outcomes between the two arms, and to identify logistical problems and unanticipated issues arising from the adaptation and delivery of a 5 week course. Discussion This trial has been designed to test the hypothesis that the benefits of delivering a structured education programme over 5 weeks are comparable to those observed after a 1 week course. The results of the trial and the qualitative sub-study will both inform the design and delivery of future DAFNE courses, and the development of structured education programmes in other fields of medicine

The heritability of mating behaviour in a fly and its plasticity in response to the threat of sperm competition.

Phenotypic plasticity is a key mechanism by which animals can cope with rapidly changeable environments, but the evolutionary lability of such plasticity remains unclear. The socio-sexual environment can fluctuate very rapidly, affecting both the frequency of mating opportunities and the level of competition males may face. Males of many species show plastic behavioural responses to changes in social environment, in particular the presence of rival males. For example, Drosophila pseudoobscura males respond to rivals by extending mating duration and increasing ejaculate size. Whilst such responses are predicted to be adaptive, the extent to which the magnitude of response is heritable, and hence selectable, is unknown. We investigated this using isofemale lines of the fruit fly D. pseudoobscura, estimating heritability of mating duration in males exposed or not to a rival, and any genetic basis to the change in this trait between these environments (i.e. degree of plasticity). The two populations differed in population sex ratio, and the presence of a sex ratio distorting selfish chromosome. We find that mating duration is heritable, but no evidence of population differences. We find no significant heritability of plasticity in mating duration in one population, but borderline significant heritability of plasticity in the second. This difference between populations might be related to the presence of the sex ratio distorting selfish gene in the latter population, but this will require investigation in additional populations to draw any conclusions. We suggest that there is scope for selection to produce an evolutionary response in the plasticity of mating duration in response to rivals in D. pseudoobscura, at least in some populations