651 research outputs found

    A new differential configuration suitable for realization of high CMRR, all-pass/notch filters

    Get PDF
    #yayıncısurumuyok# ; Tam metin hakemden geçmiş kopyadır.In this paper, a new configuration suitable for realization of differential input-differential output first order, second order all-pass and notch filters with high CMRR is given. The proposed configuration uses two negative type second-generation current conveyors (CCII-), and three admittances. Two first order and one second order all-pass filters and a notch filter (tunable if current controlled conveyor CCCII is used) are extracted from the proposed configuration. Tracking error, element mismatch, sensitivity analysis, simulation and experimental results are included

    Characterization of growth and metabolism of the haloalkaliphile Natronomonas pharaonis

    Get PDF
    Natronomonas pharaonis is an archaeon adapted to two extreme conditions: high salt concentration and alkaline pH. It has become one of the model organisms for the study of extremophilic life. Here, we present a genome-scale, manually curated metabolic reconstruction for the microorganism. The reconstruction itself represents a knowledge base of the haloalkaliphile's metabolism and, as such, would greatly assist further investigations on archaeal pathways. In addition, we experimentally determined several parameters relevant to growth, including a characterization of the biomass composition and a quantification of carbon and oxygen consumption. Using the metabolic reconstruction and the experimental data, we formulated a constraints-based model which we used to analyze the behavior of the archaeon when grown on a single carbon source. Results of the analysis include the finding that Natronomonas pharaonis, when grown aerobically on acetate, uses a carbon to oxygen consumption ratio that is theoretically near-optimal with respect to growth and energy production. This supports the hypothesis that, under simple conditions, the microorganism optimizes its metabolism with respect to the two objectives. We also found that the archaeon has a very low carbon efficiency of only about 35%. This inefficiency is probably due to a very low P/O ratio as well as to the other difficulties posed by its extreme environment

    Activation of COX-2/PGE2 Promotes Sapovirus Replication via the Inhibition of Nitric Oxide Production.

    Get PDF
    Enteric caliciviruses in the genera Norovirus and Sapovirus are important pathogens that cause severe acute gastroenteritis in both humans and animals. Cyclooxygenases (COXs) and their final product, prostaglandin E2 (PGE2), are known to play important roles in the modulation of both the host response to infection and the replicative cycles of several viruses. However, the precise mechanism(s) by which the COX/PGE2 pathway regulates sapovirus replication remains largely unknown. In this study, infection with porcine sapovirus (PSaV) strain Cowden, the only cultivable virus within the genus Sapovirus, markedly increased COX-2 mRNA and protein levels at 24 and 36 h postinfection (hpi), with only a transient increase in COX-1 levels seen at 24 hpi. The treatment of cells with pharmacological inhibitors, such as nonsteroidal anti-inflammatory drugs or small interfering RNAs (siRNAs) against COX-1 and COX-2, significantly reduced PGE2 production, as well as PSaV replication. Expression of the viral proteins VPg and ProPol was associated with activation of the COX/PGE2 pathway. We observed that pharmacological inhibition of COX-2 dramatically increased NO production, causing a reduction in PSaV replication that could be restored by inhibition of nitric oxide synthase via the inhibitor N-nitro-l-methyl-arginine ester. This study identified a pivotal role for the COX/PGE2 pathway in the regulation of NO production during the sapovirus life cycle, providing new insights into the life cycle of this poorly characterized family of viruses. Our findings also reveal potential new targets for treatment of sapovirus infection. IMPORTANCE: Sapoviruses are among the major etiological agents of acute gastroenteritis in both humans and animals, but little is known about sapovirus host factor requirements. Here, using only cultivable porcine sapovirus (PSaV) strain Cowden, we demonstrate that PSaV induced the vitalization of the cyclooxygenase (COX) and prostaglandin E2 (PGE2) pathway. Targeting of COX-1/2 using nonsteroidal anti-inflammatory drugs (NSAIDs) such as the COX-1/2 inhibitor indomethacin and the COX-2-specific inhibitors NS-398 and celecoxib or siRNAs targeting COXs, inhibited PSaV replication. Expression of the viral proteins VPg and ProPol was associated with activation of the COX/PGE2 pathway. We further demonstrate that the production of PGE2 provides a protective effect against the antiviral effector mechanism of nitric oxide. Our findings uncover a new mechanism by which PSaV manipulates the host cell to provide an environment suitable for efficient viral growth, which in turn can be a new target for treatment of sapovirus infection.Wellcome Trust (097997/Z/11/Z); Grant (2014R1A2A2A01004292) of Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning, the Korea Basic Science Institute grant (C33730), and Bio-industry Technology Development Program (315021-04) funded by the Ministry of Agriculture, Food and Rural Affairs, Republic of Korea

    No relationship between left ventricular radial wall motion and longitudinal velocity and the extent and severity of noncompaction cardiomyopathy

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Noncompaction cardiomyopathy (NCCM) is characterized by a prominent trabecular meshwork and deep intertrabecular recesses. Although systolic dysfunction is common, limited information is available on differences in wall motion of the normal compacted and noncompacted segments. The purpose of this study was to assess radial wall motion and longitudinal wall velocity in patients with NCCM, according to the extent and severity of noncompaction.</p> <p>Methods</p> <p>The study comprised 29 patients in sinus rhythm (age 41 ± 15 years, 15 men), who fulfilled stringent diagnostic criteria for NCCM and compared to 29 age and gender matched healthy controls. Segmental radial wall motion of all compacted and noncompacted segments was assessed with the standard visual wall motion score index and longitudinal systolic (Sm) wall velocity with tissue Doppler imaging of the mitral annulus. For each LV wall a normalized Sm value was calculated. The extent and severity of NC in each LV segment was assessed both in a qualitative and quantitative manner.</p> <p>Results</p> <p>Heart failure was the primary clinical presentation in half of the patients. NCCM patients had a wall motion score index of 1.68 ± 0.43 and a normalized Sm of 82 ± 20%. The total and maximal noncompaction scores were not related to the wall motion score index and the normalized Sm. NCCM patients with and without heart failure had similar total and maximal noncompaction scores.</p> <p>Conclusions</p> <p>In NCCM patient's radial wall motion and longitudinal LV wall velocity is impaired but not related to the extent or severity of noncompaction.</p

    The p53 Tumor Suppressor Is Stabilized by Inhibitor of Growth 1 (ING1) by Blocking Polyubiquitination

    Get PDF
    The INhibitor of Growth tumor suppressors (ING1-ING5) affect aging, apoptosis, DNA repair and tumorigenesis. Plant homeodomains (PHD) of ING proteins bind histones in a methylation-sensitive manner to regulate chromatin structure. ING1 and ING2 contain a polybasic region (PBR) adjacent to their PHDs that binds stress-inducible phosphatidylinositol monophosphate (PtIn-MP) signaling lipids to activate these INGs. ING1 induces apoptosis independently of p53 but other studies suggest proapoptotic interdependence of ING1 and p53 leaving their functional relationship unclear. Here we identify a novel ubiquitin-binding domain (UBD) that overlaps with the PBR of ING1 and shows similarity to previously described UBDs involved in DNA damage responses. The ING1 UBD binds ubiquitin with high affinity (Kd∼100 nM) and ubiquitin competes with PtIn-MPs for ING1 binding. ING1 expression stabilized wild-type, but not mutant p53 in an MDM2-independent manner and knockdown of endogenous ING1 depressed p53 levels in a transcription-independent manner. ING1 stabilized unmodified and six multimonoubiquitinated forms of wild-type p53 that were also seen upon DNA damage, but not p53 mutants lacking the six known sites of ubiquitination. We also find that ING1 physically interacts with herpesvirus-associated ubiquitin-specific protease (HAUSP), a p53 and MDM2 deubiquitinase (DUB), and knockdown of HAUSP blocks the ability of ING1 to stabilize p53. These data link lipid stress signaling to ubiquitin-mediated proteasomal degradation through the PBR/UBD of ING1 and further indicate that ING1 stabilizes p53 by inhibiting polyubiquitination of multimonoubiquitinated forms via interaction with and colocalization of the HAUSP-deubiquitinase with p53

    Specialist nursing and community support for the carers of people with dementia living at home: an evidence synthesis.

    Get PDF
    Specialist nurses are one way of providing support for family carers of people with dementia, but relatively little is known about what these roles achieve, or if they are more effective than roles that do not require a clinical qualification. The aim of this review was to synthesise the literature on the scope and effectiveness of specialist nurses, known as Admiral Nurses, and set this evidence in the context of other community-based initiatives to support family carers of people with dementia. We undertook a systematic review of the literature relating to the scope and effectiveness of Admiral Nurses and a review of reviews of interventions to support the family carers of people with dementia. To identify studies, we searched electronic databases, undertook lateral searches and contacted experts. Searches were undertaken in November 2012. Results are reported narratively with key themes relating to Admiral Nurses identified using thematic synthesis. We included 33 items relating to Admiral Nurses (10 classified as research) and 11 reviews evaluating community-based support for carers of people with dementia. There has been little work to evaluate specific interventions provided by Admiral Nurses, but three overarching thematic categories were identified: (i) relational support, (ii) co-ordinating and personalising support and (iii) challenges and threats to the provision of services by Admiral Nurses. There was an absence of clearly articulated goals and service delivery was subject to needs of the host organisation and the local area. The reviews of community-based support for carers of people with dementia included 155 studies but, in general, evidence that interventions reduced caregiver depression or burden was weak, although psychosocial and educational interventions may reduce depression in carers. Community support for carers of people with dementia, such as that provided by Admiral Nurses, is valued by family carers, but the impact of such initiatives is not clearly established

    Cardiac abnormalities in adults with the attenuated form of mucopolysaccharidosis type I

    Get PDF
    Background: Cardiac involvement in mucopolysaccharidosis type I (MPS I) has been studied primarily in its most severe forms. Cardiac involvement, particularly left ventricular (LV) systolic and diastolic function, in the attenuated form of MPS I is less well known. Methods: Cardiac function was prospectively investigated in 9 adult patients with the attenuated form of MPS I. All patients underwent 12-lead electrocardiography, 24 h Holter monitoring and two-dimensional echocardiography including tissue Doppler imaging (TDI). Eighteen age- and sex-matched healthy volunteers served as a control group. Results: Aortic, mitral and tricuspid valve thickening was seen in, respectively, 5 (56%), 4 (44%) and 2 (22%) patients. Moderate mitral valve stenosis was seen in 1 patient and moderate aortic stenosis in 2 patients. All patients had mild-to-moderate aortic and mitral valve regurgitation and 6 patients (67%) had mild-to-moderate tricuspid valve regurgitation. Despite normal LV dimensions, ejection fraction and mass index, MPS patients had lower mean systolic mitral annular velocities (6.1±0.6 vs 9.1±1.4 cm/s, p<0.01) compared to normal control subjects. Similarly, mean early diastolic mitral annular velocities were lower in MPS patients (7.8±0.9 vs 13.3±3.3 cm/s, p<0.01). Conclusion: MPS I patients with the attenuated phenotype have not only valvular abnormalities but also LV diastolic and systolic abnormalities
    corecore