Search results for "interactions."
showing 10 items of 1865 documents
Type III Secretion-Dependent Cell Cycle Block Caused in HeLa Cells by Enteropathogenic Escherichia coliO103
2001
ABSTRACT Rabbit enteropathogenic Escherichia coli (EPEC) O103 induces in HeLa cells an irreversible cytopathic effect characterized by the recruitment of focal adhesions, formation of stress fibers, and inhibition of cell proliferation. We have characterized the modalities of the proliferation arrest and investigated its underlying mechanisms. We found that HeLa cells that were exposed to the rabbit EPEC O103 strain E22 progressively accumulated at 4C DNA content and did not enter mitosis. A significant proportion of the cells were able to reinitiate DNA synthesis without division, leading to 8C DNA content. This cell cycle inhibition by E22 was abrogated in mutants lacking EspA, -B, and -D…
Functional evidence for GABA as modulator of the contractility of the longitudinal muscle in mouse duodenum: Role of GABAA and GABAC receptors
2007
We investigated, in vitro, the effects of gamma-aminobutyric acid (GABA) on the spontaneous mechanical activity of the longitudinal smooth muscle in mouse duodenum. GABA induced an excitatory effect, consisting in an increase in the basal tone, which was antagonized by the GABA(A)-receptor antagonist, bicuculline, potentiated by (1,2,5,6-Tetrahydropyridin-4-yl)methylphosphinic acid hydrate (TPMPA), a GABA(C)-receptor antagonist and it was not affected by phaclofen, a GABA(B)-receptor antagonist. Muscimol, GABA(A) receptor agonist, induced a contractile effect markedly reduced by bicuculline, tetrodotoxin (TTX), hexamethonium and atropine. Cis-4-aminocrotonic acid (CACA), a specific GABA(C) …
Drug interactions at GABA(A) receptors.
2002
Neurotransmitter receptor systems have been the focus of intensive pharmacological research for more than 20 years for basic and applied scientific reasons, but only recently has there been a better understanding of their key features. One of these systems includes the type A receptor for the gamma-aminobutyric acid (GABA), which forms an integral anion channel from a pentameric subunit assembly and mediates most of the fast inhibitory neurotransmission in the adult vertebrate central nervous system. Up to now, depending on the definition, 16-19 mammalian subunits have been cloned and localized on different genes. Their assembly into proteins in a poorly defined stoichiometry forms the basi…
Infection dynamics of two renal myxozoans in hatchery reared fry and juvenile Atlantic cod Gadus morhua L.
2010
SUMMARYIn order to study the infection dynamics of 2 renal myxozoans, Zschokkella hildae Auerbach, 1910 and Gadimyxa atlanticaKøie, Karlsbakk and Nylund, 2007 in cultured Atlantic cod, Gadus morhua L. aged 3–19 months, a specific single-round PCR assay and a double-label in situ hybridization protocol were developed. The results demonstrated that the 2 myxozoans show spatial separation of their development with regard to spore formation inside the renal tubules versus the collecting ducts and ureters, as well as temporal separation with Z. hildae proliferating and developing spores only once the G. atlantica infection decreases, despite the presence of both myxozoans in the smallest fry stu…
The ALHAMBRA survey: An empirical estimation of the cosmic variance for merger fraction studies based on close pairs
2014
[Aims]: Our goal is to estimate empirically the cosmic variance that affects merger fraction studies based on close pairs for the first time. [Methods]: We compute the merger fraction from photometric redshift close pairs with 10 h−1 kpc ≤ rp ≤ 50 h−1 kpc and Δv ≤ 500 km s−1 and measure it in the 48 sub-fields of the ALHAMBRA survey. We study the distribution of the measured merger fractions that follow a log-normal function and estimate the cosmic variance σv as the intrinsic dispersion of the observed distribution. We develop a maximum likelihood estimator to measure a reliable σv and avoid the dispersion due to the observational errors (including the Poisson shot noise term). [Results]: …
The ALHAMBRA survey: accurate merger fractions derived by PDF analysis of photometrically close pairs
2015
[Aims]: Our goal is to develop and test a novel methodology to compute accurate close-pair fractions with photometric redshifts. [Methods]: We improved the currently used methodologies to estimate the merger fraction fm from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space; (ii) including the variation in the luminosity of the sources with z in both the sample selection and the luminosity ratio constrain; and (iii) splitting individual PDFs into red and blue spectral templates to reliably work with colour selections.We tested the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey.…
The role of red yeast rice (RYR) supplementation in plasma cholesterol control: A review and expert opinion.
2019
1. Preamble : Hypercholesterolemia is a major risk factor for atherosclerotic cardiovascular disease (ASCVD) [1]. Increased levels of low density lipoprotein cholesterol (LDL-C) are associated with an increased risk of coronary heart disease (CHD) and many clinical trials have shown that reducing LDL-C levels significantly reduced the CHD and CVD risk [[2], [3], [4], [5]]. Thus LDL-C-lowering is the main approach for the management of cardiovascular disease. Current guidelines suggest LDL-C levels targets based on the individual CV risk; such targets can be achieved by several means, which include both lifestyle changes and pharmacological approaches [6], with statins being the cornerstone …
Promoter-Targeted Histone Acetylation of Chromatinized Parvoviral Genome Is Essential for the Progress of Infection
2015
ABSTRACT The association of host histones with parvoviral DNA is poorly understood. We analyzed the chromatinization and histone acetylation of canine parvovirus DNA during infection by confocal imaging and in situ proximity ligation assay combined with chromatin immunoprecipitation and high-throughput sequencing. We found that during late infection, parvovirus replication bodies were rich in histones bearing modifications characteristic of transcriptionally active chromatin, i.e., histone H3 lysine 27 acetylation (H3K27ac). H3K27ac, in particular, was located in close proximity to the viral DNA-binding protein NS1. Importantly, our results show for the first time that in the chromatinized …
Role for Tumor Necrosis Factor Alpha in Murine Cytomegalovirus Transcriptional Reactivation in Latently Infected Lungs
2004
ABSTRACT Interstitial pneumonia is a major clinical manifestation of primary or recurrent cytomegalovirus (CMV) infection in immunocompromised recipients of a bone marrow transplant. In a murine model, lungs were identified as a prominent site of CMV latency and recurrence. Pulmonary latency of murine CMV is characterized by high viral genome burden and a low incidence of variegated immediate-early (IE) gene expression, reflecting a sporadic activity of the major IE promoters (MIEPs) and enhancer. The enhancer-flanking promoters MIEP1/3 and MIEP2 are switched on and off during latency in a ratio of ∼2:1. MIEP1/3 latency-associated activity generates the IE1 transcript of the ie1/3 transcrip…
Enhancerless Cytomegalovirus Is Capable of Establishing a Low-Level Maintenance Infection in Severely Immunodeficient Host Tissues but Fails in Expon…
2010
ABSTRACT Major immediate-early transcriptional enhancers are genetic control elements that act, through docking with host transcription factors, as a decisive regulatory unit for efficient initiation of the productive virus cycle. Animal models are required for studying the function of enhancers paradigmatically in host organs. Here, we have sought to quantitatively assess the establishment, maintenance, and level of in vivo growth of enhancerless mutants of murine cytomegalovirus in comparison with those of an enhancer-bearing counterpart in models of the immunocompromised or immunologically immature host. Evidence is presented showing that enhancerless viruses are capable of forming restr…