28 research outputs found
Bioactive constituents of wood rot extract of tea, Camellia sinensis L.O. Kuntze against alates of low country live wood termite Glyptotermes dilatatus Bugnion and Popoff (Isoptera: Kalotermitidae)
Endocytic pathways: combined scanning ion conductance and surface confocal microscopy study
We introduce a novel high resolution scanning surface confocal microscopy technique that enables imaging of endocytic pits in apical membranes of live cells for the first time. The improved topographical resolution of the microscope together with simultaneous fluorescence confocal detection produces pairs of images of cell surfaces sufficient to identify single endocytic pits. Whilst the precise position and size of the pit is detected by the ion conductance microscope, the molecular nature of the pit, e.g. clathrin coated or caveolae, is determined by the corresponding green fluorescent protein fluorescence. Also, for the first time, we showed that flotillin 1 and 2 can be found co-localising with ~200-nm indentations in the cell membrane that supports involvement of this protein in endocytosis
When Subterranean Termites Challenge the Rules of Fungal Epizootics
Over the past 50 years, repeated attempts have been made to develop biological control technologies for use against economically important species of subterranean termites, focusing primarily on the use of the entomopathogenic fungus Metarhizium anisopliae. However, no successful field implementation of biological control has been reported. Most previous work has been conducted under the assumption that environmental conditions within termite nests would favor the growth and dispersion of entomopathogenic agents, resulting in an epizootic. Epizootics rely on the ability of the pathogenic microorganism to self-replicate and disperse among the host population. However, our study shows that due to multilevel disease resistance mechanisms, the incidence of an epizootic within a group of termites is unlikely. By exposing groups of 50 termites in planar arenas containing sand particles treated with a range of densities of an entomopathogenic fungus, we were able to quantify behavioral patterns as a function of the death ratios resulting from the fungal exposure. The inability of the fungal pathogen M. anisopliae to complete its life cycle within a Coptotermes formosanus (Isoptera: Rhinotermitidae) group was mainly the result of cannibalism and the burial behavior of the nest mates, even when termite mortality reached up to 75%. Because a subterranean termite colony, as a superorganism, can prevent epizootics of M. anisopliae, the traditional concepts of epizootiology may not apply to this social insect when exposed to fungal pathogens, or other pathogen for which termites have evolved behavioral and physiological means of disrupting their life cycle
Diurnal effects of fluoxetine and naloxone on the human hypothalamic-pituitary-adrenal axis
1. Central serotonergic pathways are hypothesized to be involved in the stimulation of hypothalamic adrenocorticotropic hormone (ACTH) secretagogue release by both circadian- and stress-induced mechanisms, We aimed to investigate this hypothesis by measuring the effect of the highly specific serotonin re-uptake inhibitor fluoxetine (FX) on ACTH and cortisol release in the morning and in the afternoon in humans, both by itself and in combination with the opioid antagonist naloxone (Nal). Naloxone causes ACTH release in humans by removing an endogenous inhibitory opioid tone on central noradrenergic pathways stimulatory to hypothalamic corticotropin-releasing hormone (CRH) secretion, Serotonergic agents may act directly or indirectly through these central noradrenergic pathways and, if so, would be expected to be additive to or synergistic with Nd in causing ACTH and cortisol release
Effects of nutrients on feeding activities of the pest termite Heterotermes tenuis (Isoptera: Rhinotermitidae)
Adrenocorticotropin Hyperresponsiveness in Myotonic-Dystrophy Following Oral Fenfluramine Administration
The plasma immunoreactive adrenocorticotropin and cortisol responses to oral fenfluramine hydrochloride (1.5 mg/kg body wt) or placebo were examined in 11 patients with myotonic dystrophy, 4 controls with facioscapulohumeral dystrophy, a similarly debilitating muscle wasting disease, and 14 normal controls in single-blind studies performed in mid-afternoon
Long Non Coding RNAs (lncRNAs) are dysregulated in Malignant Pleural Mesothelioma (MPM)
Malignant Pleural Mesothelioma (MPM) is an aggressive cancer that is often diagnosed at an advanced stage and is characterized by a long latency period (20-40 years between initial exposure and diagnosis) and prior exposure to asbestos. Currently accurate diagnosis of MPM is difficult due to the lack of sensitive biomarkers and despite minor improvements in treatment, median survival rates do not exceed 12 months. Accumulating evidence suggests that aberrant expression of long non-coding RNAs (lncRNAs) play an important functional role in cancer biology. LncRNAs are a class of recently discovered non-protein coding RNAs >200 nucleotides in length with a role in regulating transcription. Here we used NCode long noncoding microarrays to identify differentially expressed lncRNAs potentially involved in MPM pathogenesis. High priority candidate lncRNAs were selected on the basis of statistical (P3-fold difference). Expression levels of 9 candidate lncRNAs were technically validated using RT-qPCR, and biologically validated in three independent test sets: (1) 57 archived MPM tissues obtained from extrapleural pneumonectomy patients, (2) 15 cryopreserved MPM and 3 benign pleura, and (3) an extended panel of 10 MPM cell lines. RT-qPCR analysis demonstrated consistent up-regulation of these lncRNAs in independent datasets. ROC curve analysis showed that two candidates were able to separate benign pleura and MPM with high sensitivity and specificity, and were associated with nodal metastases and survival following induction chemotherapy. These results suggest that lncRNAs have potential to serve as biomarkers in MPM