Publications by authors named "Ebert S"

The relationship between the mechanical properties of cells and their molecular architecture has been the focus of extensive research for decades. The cytoskeleton, an internal polymer network, in particular determines a cell's mechanical strength and morphology. This cytoskeleton evolves during the normal differentiation of cells, is involved in many cellular functions, and is characteristically altered in many diseases, including cancer.

View Article and Find Full Text PDF

Neuronal injury in bacterial meningitis is a consequence of the direct toxicity of bacterial components and inflammatory and oxidative mechanisms. Adjunctive therapy with melatonin was investigated in vitro and in experimental meningitis. Cellular damage was reduced by treatment with melatonin in organotypic hippocampal cultures (P<.

View Article and Find Full Text PDF

Microglial cells express Toll-like receptors (TLRs) recognising exogenous and endogenous ligands. Upon stimulation with agonists of TLR2, TLR4, and TLR9, nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) were released by primary mouse microglial cell cultures. Endotoxin was most potent in stimulating microglia followed by pneumolysin, cytosine-guanosine (CpG) oligodesoxynucleotide (ODN), and Tripalmitoyl-S-glyceryl-cysteine.

View Article and Find Full Text PDF

The purpose of this cross-sectional study was to examine the impact of personality factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness), cognitive factors (sense of coherence and self-efficacy), coping resources (family and friend social support) and demographic factors (gender and ethnicity) on cigarette smoking behaviors (initiation, frequency, and amount of cigarette smoking) among college students. A total of 161 U.S.

View Article and Find Full Text PDF

Viral vector-based expression of small interfering RNAs is a promising tool for gene regulation, both in cultured cells and in animal models. In this study, we analysed the ability of adeno-associated virus-2 to function as an RNAi vector in cultured primary hippocampal neurons in vitro and in retinal ganglion cells in vivo. We demonstrate a long-lasting, highly efficient, and specific down-regulation of gene expression in vivo and in vitro by the use of bicistronic vectors.

View Article and Find Full Text PDF

Aim: This paper reports a study examining the direct effects of perceived stress, perceived availability of and satisfaction with social support, and self-efficacy, and examines the intermediary roles of perceived threat (perceived susceptibility x perceived severity), benefits, and barriers on alcohol behaviour, smoking behaviour, physical activity and nutrition behaviour, general safety behaviour and sun-protective behaviour in college students.

Background: Health behaviours formed during young adulthood may have a sustaining impact on health across later life. Entering college can be an exciting, yet stressful event for many adolescents and young adults as they face trying to adapt to changes in academic workloads, support networks, and their new environment.

View Article and Find Full Text PDF

To evaluate the developmental distribution of adrenergic cells in vivo, we inserted the Cre-recombinase gene into the locus encoding for the epinephrine biosynthetic enzyme phenylethanolamine n-methyltransferase (Pnmt) and crossed these Pnmt-Cre mice with ROSA26 reporter (R26R) mice to activate LacZ (encoding beta-galactosidase) expression in cells that were selectively derived from the adrenergic lineage. Our data show the following: (1) Insertion of Cre-recombinase into the Pnmt locus created a functional knockout of Pnmt expression with concomitant loss of epinephrine in homozygous Pnmt(Cre/Cre) mice; (2) Despite the reduction in Pnmt expression and epinephrine production in Pnmt(Cre/Cre) mice, these mice were viable and fertile, with no apparent developmental defects; (3) When crossed with R26R mice, Pnmt-Cre activation of LacZ expression faithfully recapitulated Pnmt expression in vivo; and (4) LacZ expression was activated in substantial numbers of pacemaking, conduction, and working cardiomyocytes.

View Article and Find Full Text PDF

Inherited long QT syndrome is most frequently associated with mutations in KCNQ1, which encodes the primary subunit of a potassium channel. Patients with mutations in KCNQ1 may show only the cardiac defect (Romano-Ward syndrome or RWS) or may also have severe deafness (Jervell and Lange-Nielsen syndrome or JLNS). Targeted disruption of mouse Kcnq1 models JLNS in that mice are deaf and show abnormal ECGs.

View Article and Find Full Text PDF

Conflicting results have recently emerged from human provocation studies that addressed the possible health hazards of radio frequency (RF) field exposure from mobile phones. Different findings may have resulted from exposures that are poorly defined and difficult to compare. The aim of this study was to develop guidelines to facilitate the development of exposure systems for human volunteer studies which lead to reproducible results and which provide maximum relevance with respect to the assessment of the safety of mobile technology.

View Article and Find Full Text PDF

In the present study, we identify intrinsic cardiac adrenergic (ICA) cells in the neonatal rat heart using immunofluorescent histochemical staining techniques with antibodies that specifically recognize the major enzymes in the catecholamine biosynthetic pathway. ICA cells are most concentrated near the endocardial surface of ventricular myocardium, but are also found sporadically throughout the heart. In primary cultures of neonatal rat cardiomyocytes, ICA cells are closely associated with clusters of cardiomyocytes.

View Article and Find Full Text PDF

Embryos lacking the ability to synthesize epinephrine and norepinephrine die (probably due to cardiac failure) without exogenous supplementation while mutant neonates can grow into fertile adults without supplementation. These experiments define a critical period during embryogenesis, when norepinephrine and/or epinephrine are essential for mouse development. The critical period is prior to sympathetic innervation of the heart and prior to synthesis of catecholamines by the adrenal medullae.

View Article and Find Full Text PDF

To determine whether the neonatal mouse can serve as a useful model for studying the molecular pharmacological basis of Long QT Syndrome Type 1 (LQT1), which has been linked to mutations in the human KCNQ1 gene, we measured QT intervals from electrocardiogram (ECG) recordings of wild-type (WT) and Kcnq1 knockout (KO) neonates before and after injection with the beta-adrenergic receptor agonist, isoproterenol (0.17 mg/kg, i.p.

View Article and Find Full Text PDF

Aim: This study aimed to investigate the effectiveness of a one-week triple therapy with esomeprazole, clarithromycin and metronidazole for eradication of Helicobacter pylori infection in the absence of antimicrobial resistance.

Methods: Patients testing positive for H. pylori susceptible to metronidazole and clarithromycin (E-test) were randomized to receive a one-week regimen with either esomeprazole 2 x 20 mg or omeprazole 2 x 20 mg in combination with clarithromycin 2 x 250 mg and metronidazole 2 x 400 mg.

View Article and Find Full Text PDF

Numerous medications prolong the rate-corrected QT (QTc) interval and induce arrhythmias by blocking ionic current through cardiac potassium channels composed of subunits expressed by the human ether-a-go-go-related gene (HERG). Recent reports suggest that high doses of methadone cause torsades de pointes. To date, no controlled study has described an association between methadone and QTc prolongation.

View Article and Find Full Text PDF

Toll-like receptors (TLR) play a key role in the recognition of microbial components. We investigated the differential regulation of TLR mRNA expression in bacterial and viral mouse models of central nervous system infection. Streptococcus pneumoniae meningitis led to an enhanced expression of TLR2, TLR4 and TLR9 mRNA.

View Article and Find Full Text PDF

We have previously shown that targeted disruption of the mouse Kcnq1 gene produces a long QT phenotype in vivo that requires extracardiac factors for manifestation (Casimiro et al., 2001). In the present study, we explore the hypothesis that autonomic neuroeffector transmission represents the "extra cardiac" stimulus that induces a long QT phenotype in mouse hearts lacking Kcnq1.

View Article and Find Full Text PDF

Objective: Activin is a growth and differentiation factor of many cell types, and has recently been implicated in inflammatory processes. Clinical data linking activin and its binding protein, follistatin (FS), are lacking. We measured serum levels of activin and FS in patients diagnosed with septicemia.

View Article and Find Full Text PDF

Objectives: Women have longer rate-corrected QT intervals (QTc) and are at higher risk for developing life-threatening torsades de pointes ventricular arrhythmias than men, especially after taking medications that block cardiac human ether-a-go-go-related gene (HERG)-encoded K(+) channels. The purpose of the present study was to determine if the male sex steroid hormone, dihydrotestosterone (DHT), influences QT intervals in orchiectomized (Orch) male rabbits.

Methods: ECG and whole-cell patch-clamp analyses were employed to evaluate cardiac repolarization and K(+) currents in hearts isolated from orchiectomized (Orch) male New Zealand White rabbits receiving subcutaneous sustained release pellets for either dihydrotestosterone (DHT) or placebo.

View Article and Find Full Text PDF

We have evaluated the ability of various opioid agonists, including methadone, L-alpha-acetylmethadol (LAAM), fentanyl, meperidine, codeine, morphine, and buprenorphine, to block the cardiac human ether-a-go-go-related gene (HERG) K(+) current (I(HERG)) in human cells stably transfected with the HERG potassium channel gene. Our results show that LAAM, methadone, fentanyl, and buprenorphine were effective inhibitors of I(HERG), with IC(50) values in the 1 to 10 microM range. The other drugs tested were far less potent with respect to I(HERG) inhibition.

View Article and Find Full Text PDF

Nicotinic acetylcholine receptors are pentameric, typically being composed of two or more different subunits. To investigate which receptor subtypes are active in the heart, we initiated a series of experiments using an isolated perfused rat heart (Langendorff) preparation. Nicotine administration (100 microM) caused a brief decrease (-7 +/- 2%) followed by a much larger increase (17 +/- 5%) in heart rate that slowly returned to baseline within 10 to 15 min.

View Article and Find Full Text PDF

Initial F420-dependent hydrogenation of 2,4,6-trinitrophenol (picric acid) generated the hydride sigma-complex of picrate and finally the dihydride complex. With 2,4-dinitrophenol the hydride sigma-complex of 2,4-dinitrophenol is generated. The hydride transferring enzyme system showed activity against several substituted 2,4-dinitrophenols but not with mononitrophenols.

View Article and Find Full Text PDF

Neuronal nicotinic acetylcholine receptors (nAChRs) play a significant role in sympathetic transmission in the superior cervical ganglia (SCG), with most of the signal carried by a nAChR containing an alpha3 subunit. Work has shown that transection of the postganglionic nerves (axotomy) of the SCG results in a decrease in mRNA transcripts for alpha3, alpha5, alpha7 and beta4 and in protein expression of alpha7 and beta4. To evaluate effects of axotomy on alpha3 protein in the SCG, quantitative immunoblotting was used to demonstrate a dramatic decrease (> 80%) in the levels of this subunit 4 days after axotomy.

View Article and Find Full Text PDF

A synthetic peptide corresponding to the C-terminus of the alpha 3 subunit of the rat neuronal nicotinic acetylcholine receptor (nAChR) was used to generate a rabbit polyclonal alpha 3 antibody. The specificity of this antibody was characterized by immunoblotting, immunohistochemical and immunoprecipitation techniques. Using this antibody, the relative densities of the alpha 3 subunit were quantitatively determined in different brain regions and in superior cervical ganglion (SCG).

View Article and Find Full Text PDF

KCNQ1 encodes KCNQ1, which belongs to a family of voltage-dependent K(+) ion channel proteins. KCNQ1 associates with a regulatory subunit, KCNE1, to produce the cardiac repolarizing current, I(Ks). Loss-of-function mutations in the human KCNQ1 gene have been linked to Jervell and Lange-Nielsen Syndrome (JLNS), a disorder characterized by profound bilateral deafness and a cardiac phenotype.

View Article and Find Full Text PDF