Plasma glycated CD59 (gCD59), a novel biomarker for the diagnosis, management and follow up of women with Gestational Diabetes (GDM) - protocol for prospective cohort study.

BACKGROUND: The prevalence of Gestational Diabetes (GDM) is rising and with it the number of mothers and children at risk of adverse outcomes. As treatment has been shown to reduce adverse events, it is imperative that we identify all at-risk pregnant women. In Ireland, the national standard of care is selective screening with a 2-hour 75 g oral glucose tolerance test (OGTT). Aiming for universal screening is of utmost importance but this is difficult given the length, the unfeasibility and impracticability of the OGTT. We aim to assess if the novel biomarker glycated CD59 (gCD59) is a suitable contender for the OGTT in identifying women with GDM. METHODS: In this prospective cohort study, the study participants will be consecutive pregnant women at Galway University Hospital, Galway, Ireland. Samples for the plasma gCD59 biomarker will be taken together with routine bloods at the first antenatal visit, at weeks 24-28 at the time of routine 75 g OGTT, in trimester 3- and 12-weeks post-partum for women with GDM while having their routine post-partum 75 g OGTT. The constructed database will contain baseline information on each study participant, baseline laboratory data, follow-up laboratory data and pregnancy related outcomes. We aim to recruit a total of 2,000 participants over the project period and with a national GDM prevalence of 12-13%, we will have 240-260 subjects who meet OGTT criteria for GDM. Following regional prevalence, we expect to have 34-37 women who will develop either diabetes or pre-diabetes in the early post-partum period. The sensitivity and specificity of plasma gCD59 to predict the results of the OGTT will be assessed using nonparametric estimates of the receiver operating characteristic (ROC) curves and respective area under the ROC curve (AUROC). DISCUSSION: A body of clinical and experimental evidence supports a link between the complement system, complement regulatory proteins, and the pathogenesis of diabetes complications. Building on this research, our study plans to look at the plasma gCD59 capacity to classify pregnant women with normal or abnormal glucose tolerance but also to assess if plasma gCD59 can be used as an early predictor for GDM, for adverse pregnancy outcomes and/or post-partum glucose intolerance.

Ventral striatal regulation of CREM mediates impulsive action and drug addiction vulnerability.

Impulsivity, a multifaceted behavioral hallmark of attention-deficit/hyperactivity disorder (ADHD), strongly influences addiction vulnerability and other psychiatric disorders that incur enormous medical and societal burdens yet the neurobiological underpinnings linking impulsivity to disease remain poorly understood. Here we report the critical role of ventral striatal cAMP-response element modulator (CREM) in mediating impulsivity relevant to drug abuse vulnerability. Using an ADHD rat model, we demonstrate that impulsive animals are neurochemically and behaviorally more sensitive to heroin and exhibit reduced Crem expression in the nucleus accumbens core. Virally increasing Crem levels decreased impulsive action, thus establishing a causal relationship. Genetic studies in seven independent human populations illustrate that a CREM promoter variant at rs12765063 is associated with impulsivity, hyperactivity and addiction-related phenotypes. We also reveal a role of Crem in regulating striatal structural plasticity. Together, these results highlight that ventral striatal CREM mediates impulsivity related to substance abuse and suggest that CREM and its regulated network may be promising therapeutic targets.

Stroke prevention with rivaroxaban in higher-risk populations with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major risk factor for stroke. Rivaroxaban, an oral factor Xa inhibitor, is approved for the prevention of stroke in patients with non-valvular AF. In the pivotal phase III trial ROCKET AF, rivaroxaban demonstrated non-inferiority compared with warfarin for reducing the risk of stroke or systemic embolism (SE) in patients with AF (intention-to-treat analysis), without an increased risk of major bleeding. Superior efficacy vs. warfarin was achieved while patients were on study medication. Other direct oral factor Xa inhibitors have completed phase III clinical trials in this indication. Compared with warfarin, apixaban (in the ARISTOTLE trial) and edoxaban (in the ENGAGE-AF trial) were shown to be superior or non-inferior, respectively, for reduction in stroke or SE risk in patients with AF. Baseline stroke risk, as indicated by CHADS2 scores, was lower in patients in the ARISTOTLE and ENGAGE-AF trials than in ROCKET AF. OBJECTIVES: This review discusses the main findings from ROCKET AF, specifically examining recent subgroup analyses investigating rivaroxaban use across various patient types at high risk for adverse outcomes, including those with prior stroke or transient ischaemic attack, reduced renal function, prior myocardial infarction, peripheral artery disease, heart failure or patients aged ≥ 75 years and those resident in East Asia. CONCLUSIONS: These subgroup analyses demonstrate that the treatment effect for rivaroxaban vs. warfarin is broadly consistent across a wide range of patient groups, with respect to both efficacy and safety.

Novel anticoagulants for stroke prevention in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common cardiac arrhythmia that can potentially result in stroke. Vitamin K antagonists (VKA) like warfarin were for many decades the only oral anticoagulants available for stroke prevention in patients with non-valvular atrial fibrillation (AF) at high risk of stroke. Recently, new oral anticoagulants (NOACS) have been introduced that act via direct inhibition of thrombin (dabigatran) or activated factor X (edoxaban, rivaroxaban and apixaban). Unlike VKAs, these anticoagulants do not require routine INR monitoring and posses favorable pharmacological properties. NOACs act rapidly, and have a stable and predictable dose-related anticoagulant effect with few clinically relevant drug-drug interactions. Phase III trials comparing these agents to warfarin for stroke prevention in patients with non-valvular AF demonstrated that they are at least as efficacious and safe as warfarin. Evolution of clinical guidelines to incorporate the new anticoagulants for stroke prevention in non-valvular AF may result in a reduction in the incidence of AF-related strokes. Safe and effective use of these new drugs in clinical practice requires understanding of their distinct pharmacological properties.

Clotrimazole inhibits cell proliferation in vitro and in vivo.

Cell proliferation is critically dependent on the regulated movement of ions across various cellular compartments. The antimycotic drug clotrimazole (CLT) has been shown to inhibit movement of Ca2+ and K+ across the plasma membrane. Our results show that CLT inhibits the rate of cell proliferation of normal and cancer cell lines in a reversible and dose-dependent manner in vitro. Moreover, CLT depletes the intracellular Ca2+ stores and prevents the rise in cytosolic Ca2+ that normally follows mitogenic stimulation. In mice with severe combined immunodeficiency disease (SCID) and inoculated intravenously with MM-RU human melanoma cells, daily subcutaneous injections of CLT induced a significant reduction in the number of lung metastases. Modulation of early ionic mitogenic signals and potent inhibition of cell proliferation both in vitro and in vivo are new and potentially useful clinical effects of CLT.

Terminal complement proteins C5b-9 release basic fibroblast growth factor and platelet-derived growth factor from endothelial cells.

Interactions between endothelium and vascular smooth muscle cells play a major role in the biology of the blood vessel wall. Growth factors released from endothelial cells control in part the normal and pathological proliferation of vascular smooth muscle cells. Endothelial deposits of C5b-9 proteins, the membrane attack complex of complement (MAC), have been found in a variety of pathological tissues in which cell proliferation is an early characteristic abnormality, including atherosclerosis. We have explored a possible bridging role for terminal complement C5b-9 proteins in eliciting focal signals for cell proliferation by releasing growth factors from endothelial cells. We found that both bovine aortic and human umbilical vein cells respond to the MAC by releasing basic fibroblast growth factor and platelet-derived growth factor. These mitogens stimulate DNA synthesis in Swiss 3T3, vascular smooth muscle, and glomerular mesangial cells. Based on these findings, we propose that complement-induced release of mitogens from endothelial cells is a novel pathogenic mechanism for proliferative disorders.

Nervous system Lyme disease.

Lyme disease, the multi-system infection caused by the tick-borne spirochaete Borrelia burgdorferi, can involve the nervous system, most commonly causing, alone or in combination, lymphocytic meningitis or abnormalities of cranial or peripheral nerves, the latter most typically presenting as a painful radicular syndrome. Diagnosis is based on appropriately used, standard serological tests; in instances where the central nervous system is involved, cerebrospinal fluid assessment for organism-specific antibodies can be useful. Treatment with any of several standard regimens of oral or parenteral antimicrobials is highly effective. Prolonged treatment beyond four weeks is rarely if ever warranted, and carries significant risk.

Comparison of idraparinux with vitamin K antagonists for prevention of thromboembolism in patients with atrial fibrillation: a randomised, open-label, non-inferiority trial.

BACKGROUND: Vitamin K antagonists, the current standard treatment for prophylaxis against stroke and systemic embolism in patients with atrial fibrillation, require regular monitoring and dose adjustment; an unmonitored, fixed-dose anticoagulant regimen would be preferable. The aim of this randomised, open-label non-inferiority trial was to compare the efficacy and safety of idraparinux with vitamin K antagonists. METHODS: Patients with atrial fibrillation at risk for thromboembolism were randomly assigned to receive either subcutaneous idraparinux (2.5 mg weekly) or adjusted-dose vitamin K antagonists (target of an international normalised ratio of 2-3). Assessment of outcome was done blinded to treatment. The primary efficacy outcome was the cumulative incidence of all stroke and systemic embolism. The principal safety outcome was clinically relevant bleeding. Analyses were done by intention to treat; the non-inferiority hazard ratio was set at 1.5. This trial is registered with ClinicalTrials.gov, number NCT00070655. FINDINGS: The trial was stopped after randomisation of 4576 patients (2283 to receive idraparinux, 2293 to receive vitamin K antagonists) and a mean follow-up period of 10.7 (SD 5.4) months because of excess clinically relevant bleeding with idraparinux (346 cases vs 226 cases; 19.7 vs 11.3 per 100 patient-years; p<0.0001). There were 21 instances of intracranial bleeding with idraparinux and nine with vitamin K antagonists (1.1 vs 0.4 per 100 patient-years; p=0.014); elderly patients and those with renal impairment were at greater risk of such complications. There were 18 cases of thromboembolism with idraparinux and 27 cases with vitamin K antagonists (0.9 vs 1.3 per 100 patient-years; hazard ratio 0.71, 95% CI 0.39-1.30; p=0.007), satisfying the non-inferiority criterion. There were 62 deaths with idraparinux and 61 with vitamin K anatagonists (3.2 vs 2.9 per 100 patient-years; p=0.49). INTERPRETATION: In patients with atrial fibrillation at risk for thromboembolism, long-term treatment with idraparinux was no worse than vitamin K antagonists in terms of efficacy, but caused significantly more bleeding.

Prolactin Is a Strong Candidate for the Regulation of Luteal Steroidogenesis in Vizcachas (Lagostomus maximus).

Prolactin (PRL) is essential for the maintenance of the corpora lutea and the production of progesterone (P4) during gestation of mice and rats, which makes it a key factor for their successful reproduction. Unlike these rodents and the vast majority of mammals, female vizcachas (Lagostomus maximus) have a peculiar reproductive biology characterized by an ovulatory event during pregnancy that generates secondary corpora lutea with a consequent increment of the circulating P4. We found that, although the expression of pituitary PRL increased steadily during pregnancy, its ovarian receptor (PRLR) reached its maximum in midpregnancy and drastically decreased at term pregnancy. The luteinizing hormone receptor (LHR) exhibited a similar profile than PRLR. Maximum P4 and LH blood levels were recorded at midpregnancy as well. Remarkably, the P4-sinthesizing enzyme 3ß-HSD accompanied the expression pattern of PRLR/LHR throughout gestation. Instead, the luteolytic enzyme 20α-HSD showed low expression at early and midpregnancy, but reached its maximum at the end of gestation, when PRLR/LHR/3ß-HSD expressions and circulating P4 were minimal. In conclusion, both the PRLR and LHR expressions in the ovary would define the success of gestation in vizcachas by modulating the levels of 20α-HSD and 3ß-HSD, which ultimately determine the level of serum P4 throughout gestation.

Ca2+-activated K+ efflux limits complement-mediated lysis of human erythrocytes.

The lytic effect of complement on human erythrocytes has been reported by others to increase when Na+ is substituted for K+ in the external medium. In this paper we have investigated the hypothesis that net loss of K+ through a K+ transport pathway protects erythrocytes from complement-induced colloidosmotic swelling and lysis. Antibody-sensitized human erythrocytes containing different intracellular cation concentrations (nystatin treatment) were exposed to low concentrations of guinea pig serum in media of different cation composition; complement lysis was assessed by the release of hemoglobin and the volume of the surviving cells estimated by their density distribution profiles. Complement-dependent swelling and lysis of erythrocytes (a) were limited by the presence of an outwardly directed K+ electrochemical gradient and (b) were enhanced by carbocyanine, a specific inhibitor of the Ca2+-activated K+ transport pathway, and by absence of Ca2+ in the external medium. We propose that during complement activation a rising cytosolic calcium triggers the Ca2+-activated K+ permeability pathway, the Gardos effect, produces a net K+, Cl- and water loss, and thus limits the colloidosmotic swelling and lysis of erythrocytes.

Terminal complement complex C5b-9 stimulates mitogenesis in 3T3 cells.

The membrane attack complex of complement (MAC) can induce reversible changes in cell membrane permeability resulting in significant but transient intracellular ionic changes in the absence of cell lysis. Because ion fluxes and cytosolic ionic changes are integral steps in the signaling cascade initiated when growth factors bind to their receptors, we hypothesized that the MAC-induced reversible changes in membrane permeability could stimulate cell proliferation. Using purified terminal complement components we have documented a mitogenic effect of the MAC for quiescent murine 3T3 cells. The MAC enhances the mitogenic effects of serum and PDGF, and also stimulates cell proliferation in the absence of other exogenous growth factors. MAC-induced mitogenesis represents a novel effect of the terminal complement complex that could contribute to focal tissue repair or pathological cell proliferation locally at sites of complement activation.

Properties of the Na+-K+ pump in human red cells with increased number of pump sites.

We studied the Na+/K+ pump in red cells from an obese human subject (MAJ) in which the number of pumps/cell was 10-20 times higher than normal. Through measurements of the kinetic properties of several modes of operation of the Na+/K+ pump we determined that the pumps in MAJ cells are kinetically normal. In the presence of adequate metabolic substrate the maximum rates of Na+ pumping and lactate production saturated at 60 and 12 nmol/1 cell per h, respectively. Under physiological conditions pump and "leak" Na+ fluxes were similar in MAJ and normal cells. Since internal Na+ was lower in MAJ than in normal cells (Nai+ approximately 2 and 8 mmol/1 cell, respectively), we conclude that the reduction in cell Na+ allows the Na+/K+ pump in MAJ cells to operate at lower fraction of maximum capacity and to compensate for the increased number of pumps.

Complement induces a transient increase in membrane permeability in unlysed erythrocytes.

The effects of low concentrations of human serum on antibody-sensitized sheep erythrocytes (EA) were studied. We report that exposure to low concentrations of serum induced a large but transient increase in the membrane permeability of those EA that do not lyse. This change in the permeability of the erythrocyte membrane resulted in net uptake of Na+ and decrease in cell K+, without affecting the total internal cation content. Although exposure to serum also allowed for net uptake of larger molecules like L-glucose, it did not lead to cell swelling. Experiments with sera genetically deficient in one of the terminal complement components showed that C8, but not C9, was required to produce the observed change in membrane permeability. Therefore, we propose that the C5b-8 complex can mediate the transient increase in permeability observed in unlysed erythrocytes during complement activation by whole serum.

Diagnosis and management of acute encephalitis.

Encephalitis is typically viral (approximately half of diagnosed cases) or autoimmune (about a quarter) with the remainder remaining undiagnosable at this time. All require general supportive care but only a minority requires intensive care admission - in these intubation, to protect the airway or to treat status epilepticus with anesthetic drugs, may be needed. In some dysautonomia with wide blood pressure fluctuations is the principal concern. Remarkably, in addition to supportive care, specific treatment options are available for the majority - immune-modulating therapy for those with autoimmune disorders, antiviral therapy for herpes simplex 1 and 2, and varicella-zoster encephalitis. Flavivirus infections (West Nile, Japanese encephalitis, tick-borne encephalitis) remain the most common other identified cause of encephalitis but no specific intervention is available. Overall long-term outcomes are favorable in the majority of patients with encephalitis, a proportion that hopefully will improve with further advances in diagnostic technology and therapeutic interventions.

Anticancer effects of thiazolidinediones are independent of peroxisome proliferator-activated receptor gamma and mediated by inhibition of translation initiation.

The thiazolidinedione (TZD) class of peroxisome proliferator-activated receptor (PPAR) gamma ligands, known for their ability to induce adipocyte differentiation and increase insulin sensitivity, also exhibits anticancer properties. Currently, TZDs are being tested in clinical trials for treatment of human cancers expressing high levels of PPARgamma because it is assumed that activation of PPARgamma mediates their anticancer activity. Using PPARgamma(-/-) and PPARgamma(+/+) mouse embryonic stem cells, we report here that inhibition of cell proliferation and tumor growth by TZDs is independent of PPARgamma. Our studies demonstrate that these compounds block G(1)-S transition by inhibiting translation initiation. Inhibition of translation initiation is the consequence of partial depletion of intracellular calcium stores and the resulting activation of protein kinase R that phosphorylates the alpha subunit of eukaryotic initiation factor 2 (eIF2), thus rendering eIF2 inactive. PPARgamma-independent inhibition of translation initiation most likely accounts for the anticancer properties of thiazolidinediones.

Inhibition of translation initiation mediates the anticancer effect of the n-3 polyunsaturated fatty acid eicosapentaenoic acid.

Eicosapentaenoic acid (EPA), an n-3 polyunsaturated fatty acid that is abundant in the fish-based diets of populations that exhibit a remarkably low incidence of cancer, exerts anticancer activity in vitro and in animal models of experimental cancer. Here we define the molecular basis for the anticancer effects of EPA. EPA inhibits cell division by inhibiting translation initiation. This is a consequence of the ability of EPA to release Ca2+ from intracellular stores while inhibiting their refilling via capacitative Ca2+ influx that results in partial emptying of intracellular Ca2+ stores and thereby activation of protein kinase R. Protein kinase R phosphorylates and inhibits eukaryotic initiation factor 2alpha, resulting in inhibition of protein synthesis at the level of translation initiation, preferentially reducing the synthesis and expression of growth-regulatory proteins, including G1 cyclins, and causes cell cycle arrest in G1. In a KLN-205 squamous cell carcinoma mouse model, daily oral administration of EPA resulted in a significant reduction of tumor size and expression of cyclin D1 in the tumor tissues. Furthermore, EPA-treated tumors showed a significant increase in the proportion of diploid cells, indicative of cell cycle arrest in G0-G1, and a significant reduction of malignant hypertetraploid cells. These results characterize EPA as a member of an emerging new class of anticancer compounds that inhibit translation initiaton.

A voltage-activated cation transport pathway associated with the sodium pump.

In proteoliposomes containing reconstituted shark Na,K-ATPase, inside positive potentials open a cation conductance characterized by a voltage-dependence very similar to that found in mammalian erythrocytes. In both proteoliposomes and erythrocytes, the voltage-activated pathway is inhibited by external oligomycin, which traps the Na,K-ATPase in a Na-occluded E1 form. These results indicate that a cation permeable pathway, activated by inside positive potentials, can be ascribed to the Na-K pump--possibly through interaction with its gating mechanism.

Palytoxin induces an increase in the cation conductance of red cells.

Palytoxin (PTX), isolated from the marine soft coral Palythoa tuberculosa, increases the cation conductance of human red cell membranes. In the presence of 10(-10) M PTX and 10(-5) M DIDS, the membrane potential approximates the equilibrium potential for Na+ or K+ rather than Cl-. Even in the absence of DIDS, the Na+ and K+ conductances were greater than the Cl- conductance. The selectivity of the PTX-induced cation conductance is K+ greater than Rb+ greater than Cs+ greater than Na+ greater than Li+ much greater than choline+ greater than TEA+ much greater than Mg2+. Measurements of K+ efflux revealed two apparent sites for activation by PTX, one with a Kal of 0.05 nM and a maximum flux, nu max1, of 1.4 mol/liter of cells per h and another with a Ka2 of 98 nM and a nu max2 of 24 mol/liter of cells per h. These effects of PTX are completely blocked by external ouabain (300 microM) and prevented by internal vanadate (100 microM). When the PTX channels are open, the Na,K pumps do not catalyze ATP hydrolysis. Upon thorough washout of cells exposed to about five molecules of PTX/pump, the Na,K pump of these cells operates normally. Blockage of the positively charged NH2 terminus of PTX with a p-bromobenzoyl group reduces the potency of the compound to induce Na and K fluxes by at least a factor of 100, and to compete with the binding of [3H]ouabain by at least a factor of 10. These data are consistent with the conclusion that PTX binds reversibly to the Na,K pumps in the red cell membrane and opens a (10-pS) channel equally permeable to Na and K at or near each pump site.

Antiarrhythmic drug therapy and cardiac mortality in atrial fibrillation. The Stroke Prevention in Atrial Fibrillation Investigators.

BACKGROUND AND OBJECTIVES: The relation between cardiac mortality and antiarrhythmic drug administration has not been fully determined. This relation was analyzed in 1,330 patients enrolled in the Stroke Prevention in Atrial Fibrillation Study, a randomized clinical trial comparing warfarin, aspirin and placebo for the prevention of ischemic stroke or systemic embolism in patients with nonvalvular atrial fibrillation. METHODS: Patients who received antiarrhythmic drug therapy for atrial fibrillation in this study were compared with patients not receiving antiarrhythmic agents. The relative risk of cardiac mortality, including arrhythmic death, in patients receiving antiarrhythmic drug therapy was determined and adjusted for other cardiac risk factors. RESULTS: In patients receiving antiarrhythmic drug therapy, cardiac mortality was increased 2.5-fold (p = 0.006, 95% confidence interval [CI] 1.3 to 4.9) and arrhythmic death was increased 2.6-fold (p = 0.02, 95% CI 1.2 to 5.6). Among patients with a history of congestive heart failure, those given antiarrhythmic medications had a relative risk of cardiac death of 4.7 (p less than 0.001, 95% CI 1.9 to 11.6) compared with that of patients not so treated; the relative risk of arrhythmic death in the treated group was 3.7 (p = 0.01, 95% CI 1.3 to 10.4). Patients without a history of congestive heart failure had no increased risk of cardiac mortality (relative risk 0.70, 95% CI 0.2 to 3.1) during antiarrhythmic drug therapy. After exclusion of 23 patients with documented ventricular arrhythmias and adjustment for other variables predictive of cardiac death, patients receiving antiarrhythmic drugs were not at increased risk of cardiac death or arrhythmic death. However, in patients with a history of heart failure who received antiarrhythmic drug therapy, the relative risk of cardiac death was 3.3 (p = 0.05, 95% CI 0.99 to 11.1) and that of arrhythmic death was 5.8 (p = 0.009, 95% CI 1.5 to 21.7) compared with the risk in patients not taking antiarrhythmic medications. CONCLUSIONS: Although antiarrhythmic drug therapy was not randomly determined in this trial, the data suggest that in patients with atrial fibrillation and a history of congestive heart failure, the risk of such therapy may outweigh the potential benefit of maintaining sinus rhythm.