Gut microbiota modulates type I interferon and antibody-mediated immune responses in chickens infected with influenza virus subtype H9N2.

Commensal gut microbes play a critical role in shaping host defences against pathogens, including influenza viruses. The current study was conducted to assess the role and mechanisms of action of commensal gut microbiota on the innate and antibody-mediated responses of layer chickens against influenza virus subtype H9N2. A total of 104 one-day-old specific pathogen free chickens were assigned to either of the four treatments, which included two levels of antibiotics treatment (ABX- and ABX+) and two levels of H9N2 virus infection (H9N2- and H9N2+). At day 17 of age, chickens in the H9N2+ group were infected via the oral-nasal route with 400 µl of 107 TCID50/ml (200 µl/each route). Oropharyngeal and cloacal swabs at days 1, 3, 5, 7 and 9 post-infection (p.i.) for virus shedding, tissue samples at 12 h, 24 h and 36 h p.i. for mRNA measurement, and serum samples at days 7 and 14 p.i. for hemagglutination inhibition (HI) assay and IgG antibodies were collected. Virus shedding analysis showed that antibiotic treated (depleted)-H9N2 virus infected chickens showed a significantly higher oropharyngeal virus shedding at all time points, and cloacal shedding at days 3 and 5 p.i. compared to control treated (undepleted)-H9N2 infected chickens. Analysis of mRNA expression showed that infection of depleted chickens with H9N2 virus resulted in significantly down-regulated type I interferon responses both in the respiratory and gastrointestinal tracts compared to undepleted-H9N2 infected chickens. However, antibody-mediated immune response analysis showed a significantly higher HI antibody titre and IgG levels in the serum of chickens depleted with antibiotics and infected with H9N2 virus compared to undepleted-H9N2 infected chickens. In conclusion, findings from the current study suggest that the gut microbiota of chickens plays an important role in the initiation of innate responses against influenza virus infection, while the antibody-mediated immune response remains unaffected.

Central serotonergic function in parasuicide.

1. Central 5-HT is thought to be involved in neuronal inhibition and as such as a modulating influence in restraining the organism from responding to (e.g., especially adverse) stimuli. 2. Evidence for a role of central 5-HT in suicide arises from reduced concentrations of brain 5-HT or 5-HIAA in brain stem, reduced binding of [3-H]-IMI in brain tissue of frontal cortex/hypothalamus, and increased binding of radioligands to 5-HT-2 receptors in the frontal cortex. 3. Evidence for a role of central 5-HT in parasuicide arises from reduced concentrations of lumbar CSF 5-HIAA, reduced PRL responses to d,l-fenfluramine challenge, and increased CORT responses to 5-HTP challenge. 4. Since reduced central 5-HT activity appears to be consistently associated with impulsive aggression, it is possible that suicidal and parasuicidal acts in individuals with evidence of reduced central 5-HT activity are a manifestation of reduced impulse control. 5. Agents which enhance central 5-HT function and/or diminish the activity of neuronal systems involved in arousal (e.g. norepinephrine or dopamine) should be efficacious in reducing parasuicidal behavior.

Assessment of methods of destruction of Syphacia muris eggs.

An investigation was performed to identify methods suitable for decontamination of equipment being transferred from a facility contaminated with Syphacia muris to a new facility. Perianal samples were taken on clear sticky tape from rats known to be infected with S. muris. Tapes and attached worm eggs were treated with ethylene oxide, formaldehyde fumigation, potassium peroxysulphate, chlorine dioxide and didecyl di-methyl ammonium chloride, chlorine dioxide, alcohol/chlorhexidine, 100 degrees C dry heat for 30 min, ultraviolet light (UV), or left for 4 weeks at room temperature. The subsequent viability of the eggs was compared to untreated control samples. Heat and ethylene oxide produced a 100% kill rate of S. muris eggs. Formaldehyde gas and chlorine dioxide treatments showed marked effectiveness, with the number of eggs killed at 94% and 96%, respectively, while the other agents showed less efficacy (36-78% eggs killed). The percentage of eggs not hatching in the controls was 21%. Since so few agents were effective against S. muris eggs, care should be taken when choosing a method for decontaminating a facility.

What does a house-surgeon on call for the wards do?

This survey shows that the number and type of out-of-hours calls arising from general surgical inpatients in a service of 181 beds can be satisfactorily handled by an on-call house-surgeon, covering all the firms. The house-surgeon must have readily available support from the registrar on duty for the few difficult problems, and the firms must all do service ward-rounds on Saturdays and Sundays. This method of staffing at night and at weekends is economical but the work involved in the weekend rounds should be recognised.