Immunosympathectomy and avoidance behaviour in mice

W. B. Cannon and his co-workers during the 1930's had purported to have demonstrated the non-essential character of the sympathetic nervous system's role in mediating emotion, but later workers using behavioural studies have tended to implicate the system in emotional behaviour. In this thesis an immunological technique was used to induce hypotrophic growth in the sympathetic nervous system of neonatal rodents. The injection technique used a split- litter design with the control neonates being injected with normal horse serum (NHS) .Following failure to obtain behavioural separation between the immunosympathectomized (IS) and the control (NHS) litter- mates using standard active and passive avoidance tasks it was argued that the time course of these procedures allowed ample opportunity for internal compensatory mechanisms to mask any essential differences. Accordingly an avoidance task (startle response) with a very short time course was used to test the animals. This task also failed to show unequivocal behavioural separation. Measuring the catecholamine metabolism of the adrenals some evidence was obtained which showed that IS mice metabolized larger amounts of the sympathetic nervous system's transmitter substance, noradrenaline, when subjected to a novel or an avoidance task. Evidence was examined on the essential interaction between the sympatho-adrenal medulla and the pituitary-adrenal cortex axis. It was concluded that certain controls are essential if an unambiguous demonstration is to be made of these two important central nervous system's efferent outflows in emotional states. IS mice were placed on free operant avoidance schedules in specially constructed apparatus. The final experiment reported concerns an attempt to further reduce the range of IS mice adaptive responses by the use of an inclined alleyway avoidance task interpolated between two equal periods of free operant avoidance responding. It was finally concluded that unequivocal behavioural separation, using avoidance tasks, has not been shown between IS and control litterraate mice either in this thesis or other published work. Hypotheses are discussed as to why this should be so

Influence of fuselage on propeller design

In the present paper I shall not consider the problem of the best arrangement of airplane and propeller, but only a simple method for designing a propeller for a given arrangement of airplane parts. The inflow to the propeller and hence the efficiency of the propeller is affected most by the fuselage

Pressure-distribution measurements on a tapered wing with a partial-span split flap in curved flight

Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a tapered wing to determine the rolling and the yawing moments due to an angular velocity in yaw. The model was tested at 0 degree and 5 degree pitch; 0 degree, 5 degree, and 10 degree yaw; and with split flaps covering 25, 50, 75, and 100 percent of the wing span and deflected 60 degrees. The results are given in the form of load distributions and as calculated moment coefficients. The experimental values of rolling- and yawing- moment coefficients were in fairly close agreement with theory

Pressure-distribution Measurements on a Tapered Wing with a Full-span Split Flap in Curved Flight

Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a tapered wing to determine the rolling and yawing moments due to an angular velocity in yaw. The model was tested at 0 degree and 5 degrees pitch, -1 degree and 5 degree yaw, and with a full-span flap deflected 60 degrees. The results are given in the form of span load distributions and in calculated moment coefficients. The rolling-moment coefficients are in fairly close agreement with those derived by means of a simple approximate theory even for high deflection of the full-span flap

Physiologic Cold Shock Increases Adherence of Moraxella catarrhalis to and Secretion of Interleukin 8 in Human Upper Respiratory Tract Epithelial Cells

Moraxella catarrhalis, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid and prolonged downshifts of environmental temperature when humans breathe cold air. In the present study, we show that a 26°C cold shock up-regulates the expression of UspA1, a major adhesin and putative virulence factor of M. catarrhalis, by prolonging messenger RNA half-life. Cold shock promotes M. catarrhalis adherence to upper respiratory tract cells via enhanced binding to fibronectin, an extracellular matrix component that mediates bacterial attachment. Exposure of M. catarrhalis to 26°C increases the outer membrane protein-mediated release of the proinflammatory cytokine interleukin 8 in pharyngeal epithelial cells. Furthermore, cold shock at 26°C enhances the binding of salivary immunoglobulin A on the surface of M. catarrhalis. These data indicate that cold shock at a physiologically relevant temperature of 26°C affects the nasopharyngeal host-pathogen interaction and may contribute to M. catarrhalis virulenc

Down-regulation of porin M35 in Moraxella catarrhalis by aminopenicillins and environmental factors and its potential contribution to the mechanism of resistance to aminopenicillins

Objectives The outer membrane protein M35 of Moraxella catarrhalis is an antigenically conserved porin. Knocking out M35 significantly increases the MICs of aminopenicillins. The aim of this study was to determine the biological mechanism of this potentially new antimicrobial resistance mechanism of M. catarrhalis and the behaviour of M35 in general stress situations. Methods PCR using m35-specific primers was used to detect the m35 gene in clinical isolates. The m35 mRNA expression of strains 300, O35E and 415 after exposure to amoxicillin and different stress conditions was measured by real-time PCR and normalized in relation to their 16S rRNA expression. The expression of M35 protein was analysed by SDS-PAGE and western blotting. Results Screening of 52 middle ear isolates resulted in positive PCR products for all tested strains. The analysis of m35 mRNA expression after amoxicillin treatment showed 24%-85% down-regulation compared with the respective amoxicillin-free controls in all three strains tested. Also, analysis of protein concentrations revealed lower M35 expression after growth with amoxicillin. Investigation of M35 during general stress responses showed down-regulation of the porin with growth at 26°C and 42°C, under hyperosmolar stress and under iron restriction. Conclusions The reduced expression of M35 after aminopenicillin exposure indicates a novel resistance mechanism against aminopenicillins in M. catarrhalis, which may be relevant in vivo. The differences in expression after different stress treatments demonstrate that M35 is involved in general stress response

Determination of the spatial and temporal variation of tropospheric water vapour using CGPS networks

Tropospheric water vapour is the main limiting factor in using GPS to determine crustal deformation at highest accuracy. On the other hand, it is an important variable to monitor meteorological and climatic processes. This paper discusses both aspects: the modelling of tropospheric water vapour using meteorological data as well as the determination of the integrated amount of water vapour and its spatiotemporal variation using GPS data. Switzerland has been chosen as experiment area. The Swiss continuous GPS (CGPS) network AGNES is used as a reference network, which represents a realistic scenario for GPS-based water vapour determination. Data of the Swiss numerical weather model aLMo are used for systematic comparison and validation. For the first aspect, integrated tropospheric wet refractivity values are determined from meteorological measurements and compared with GPS path delays. An overall agreement of 1 cm of zenith wet path delay was achieved. For the second aspect a tomographic approach has been developed. A total of 6720 GPS-determined profiles are compared with data of the numerical weather model and radio soundings. The results are statistically evaluated and systematically compared with each other. A correlation between the accuracy and the weather situation was found. Overall, an agreement of 5-7 ppm (refractivity unit) was obtained compared to aLMo. The use of GPS-determined path delays from a permanent GPS network is the recommended method to correct GPS measurements. In all other cases, the two methods presented (COITROPA, COMEDIE) are a feasible alternative to determine path delays accurately. Furthermore, GPS is a convenient application to determine the amount of water vapour in the troposphere. It is demonstrated that the vertical distribution of water vapour can be deduced by applying the tomographic approac

Physiologic cold shock of Moraxella catarrhalis affects the expression of genes involved in the iron acquisition, serum resistance and immune evasion

<p>Abstract</p> <p>Background</p> <p><it>Moraxella catarrhalis</it>, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid downshifts of environmental temperature when humans breathe cold air. It was previously shown that the prevalence of pharyngeal colonization and respiratory tract infections caused by <it>M. catarrhalis </it>are greatest in winter. The aim of this study was to investigate how <it>M. catarrhalis </it>uses the physiologic exposure to cold air to upregulate pivotal survival systems in the pharynx that may contribute to <it>M. catarrhalis </it>virulence.</p> <p>Results</p> <p>A 26°C cold shock induces the expression of genes involved in transferrin and lactoferrin acquisition, and enhances binding of these proteins on the surface of <it>M. catarrhalis</it>. Exposure of <it>M. catarrhalis </it>to 26°C upregulates the expression of UspA2, a major outer membrane protein involved in serum resistance, leading to improved binding of vitronectin which neutralizes the lethal effect of human complement. In contrast, cold shock decreases the expression of Hemagglutinin, a major adhesin, which mediates B cell response, and reduces immunoglobulin D-binding on the surface of <it>M. catarrhalis</it>.</p> <p>Conclusion</p> <p>Cold shock of <it>M. catarrhalis </it>induces the expression of genes involved in iron acquisition, serum resistance and immune evasion. Thus, cold shock at a physiologically relevant temperature of 26°C induces in <it>M. catarrhalis </it>a complex of adaptive mechanisms that enables the bacterium to target their host cellular receptors or soluble effectors and may contribute to enhanced growth, colonization and virulence.</p

Topical curcumin can inhibit deleterious effects of upper respiratory tract bacteria on human oropharyngeal cells in vitro: potential role for patients with cancer therapy induced mucositis?

Purpose: Curcumin exerts its anti-inflammatory activity via inhibition of nuclear factor κB. Oropharyngeal epithelia and residing bacteria closely interact in inflammation and infection. This in vitro model investigated the effects of curcumin on bacterial survival, adherence to, and invasion of upper respiratory tract epithelia, and studied its anti-inflammatory effect. We aimed to establish a model, which could offer insights into the host-pathogen interaction in cancer therapy induced mucositis. Methods: Moraxella catarrhalis (Mcat) and the oropharyngeal epithelial cell line Detroit 562 were used. Time-kill curves assessed the inhibition of bacterial growth and adherence assays and gentamicin protection assays determined the effect of curcumin-preincubated cells on bacterial adherence and invasion. Curcumin-mediated inhibition of pro-inflammatory activation by Mcat was determined via interleukin-8 concentrations in the supernatants. The synergistic role of secretory IgA (sIgA) on adherence was investigated. Results: Curcumin was bactericidal at concentrations >50µM. Preincubation of Detroit cells for 60min demonstrated that concentrations >100µM inhibited bacterial adherence. Together with sIgA, curcumin inhibited adherence at concentrations ≥50µM. Both 100 and 200µM curcumin significantly inhibited Mcat cell invasion. Finally, curcumin inhibited Mcat-induced pro-inflammatory activation by strongly suppressing IL-8 release. At a concentration of 200µM, 10min of curcumin exposure inhibited IL-8 release significantly, and complete suppression required a pre-exposure time of ≥45min. Conclusion: Curcumin, in clinically relevant concentrations for topical use, displayed strong antibacterial effect against a facultative upper respiratory tract pathogen by inhibiting bacterial growth, adherence, invasion, and pro-inflammatory activation of upper respiratory tract epithelial cells in vitr