Outdoor or organic farming demands robust chickens that are able to combat common infections before they spread to the flock. Priming the immune system of the chickens early in life with ...micro-organisms that they will encounter later in life prepares chickens to a life in environments where they are subjected to a more natural level of infection pressure. Also, exposure to non-infectious stressful situations may prepare the immune system to combat infectious challenges. The present study investigated whether the immune system could be primed by applying small doses of infective material to the chicken flock or by exposure to short-term non-infectious stimulation, and whether the effect of those stimuli would depend on the genetic material chosen. The effect of the stimulations was examined on selected immunological variables in two chicken strains, using small amounts of manure and litter from other chickens or short-term heat stress, respectively. After 6 weeks of treatment, all chickens were subjected to an Escherichia coli infection and followed for another 3 weeks. Measures of body weight gain, chicken mannan-binding lectin (cMBL), percentage of CD4+ and MHCII+ lymphocytes, mean fluorescence intensity (m.f.i.) of CD4 on CD4+ cells and MHCII on MHCII+ cells and antibody titres to E. coli were taken. In conclusion, the chickens redistribute lymphocyte populations in peripheral blood in response to potentially infectious agents as well as to stressful non-infectious treatments. Responses to stress situations were dependent on the frequencies of stress exposures and on the chicken breed. This may reflect the superiority of one breed over another in adapting to treatments or in discriminating whether a treatment is harmless or dangerous. However, the differences did not influence the disease resistance to infection with a mixture of E. coli O2, O11 and O78 in the present study.
In chickens, the nematode Ascaridia galli is found with prevalences of up to 100% causing economic losses to farmers. No avian nematode vaccines have yet been developed and detailed knowledge about ...the chicken immune response towards A. galli is therefore of great importance. The objective of this study was to evaluate the induction of protective immune responses to A. galli soluble antigen by different immunization routes. Chickens were immunized with a crude extract of A. galli via an oral or intra-muscular route using cholera toxin B subunit as adjuvant and subsequently challenged with A. galli. Only chickens immunized via the intra-muscular route developed a specific A. galli antibody response. Frequencies of γδ T cells in spleen were higher 7 days after the first immunization in both groups but only significantly so in the intra-muscularly immunized group. In addition, systemic immunization had an effect on both Th1 and Th2 cytokines in caecal tonsils and Meckel's diverticulum. Thus both humoral and cellular immune responses are inducible by soluble A. galli antigen, but in this study no protection against the parasite was achieved.
Potent vaccine efficiency is crucial for disease control in both human and livestock vaccination programmes. Free range chickens and chickens with access to outdoor areas have a high risk of ...infection with parasites includingAscaridia galli, a gastrointestinal nematode with a potential influence on the immunological response to vaccination against other infectious diseases. The purpose of this study was to investigate whetherA. galliinfection influences vaccine-induced immunity to Newcastle Disease (ND) in chickens from an MHC-characterized inbred line. Chickens were experimentally infected withA. galliat 4 weeks of age or left as non-parasitized controls. At 10 and 13 weeks of age half of the chickens were ND-vaccinated and at 16 weeks of age, all chickens were challenged with a lentogenic strain of Newcastle disease virus (NDV).A. galliinfection influenced both humoral and cell-mediated immune responses after ND vaccination. Thus, significantly lower NDV serum titres were found in theA. galli-infected group as compared to the non-parasitized group early after vaccination. In addition, theA. galli-infected chickens showed significantly lower frequencies of NDV-specific T cells in peripheral blood three weeks after the first ND vaccination as compared to non-parasitized chickens. Finally,A. gallisignificantly increased local mRNA expression of IL-4 and IL-13 and significantly decreased TGF-ß4 expression in the jejunum two weeks after infection withA. galli. At the time of vaccination (six and nine weeks afterA. galliinfection) the local expression in the jejunum of both IFN-? and IL-10 was significantly decreased inA. galli-infected chickens. Upon challenge with the NDV LaSota strain, viral genomes persisted in the oral cavity for a slightly longer period of time inA. galli-infected vaccinees as compared to non-parasitized vaccinees. However, more work is needed in order to determine if vaccine-induced protective immunity is impaired inA. galli-infected chickens.
Mannan-binding lectin (MBL) is a glycoprotein and a member of the C-type lectin super family, the collectin family, and the acute phase protein family. The MBL exerts its function by directly binding ...to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonization or complement activation via MBL-associated serine proteases (MASP)-1 and -2. Thus, MBL plays a major role in the first-line innate defense against pathogens. We investigated the MBL concentrations in serum during experimental infectious bronchitis virus (IBV) infections in chickens. The results showed that the acute phase MBL response to infection with IBV was, to a degree (P < 0.0068), dependent on whether the chickens were inoculated after 12 h of rest (dark) or after 12 h of activity (light). The acute phase response in chickens challenged after 12 h of activity peaked after 4.6 d with an increase of 24%, whereas the acute phase response in chickens challenged after 12 h of rest peaked after 3.1 d with an increase of 51%. The specific antibody titer against IBV was also tested, and a difference (P < 0.0091) between the two experimental groups was found with peak titer values of 6,816 and 4,349. However, the highest value was found in chickens inoculated after 12 h of activity. Thus, an inverse relation exists between the MBL response and the IBV specific antibody response. The ability of MBL to activate the complement cascade was tested in a heterologous system by deposition of human C4 on the chicken MBL/MASP complex. The complement activation was directly associated with the concentration of MBL in serum, indicating neutralization of the virus before the humoral antibody response took over.
Little is known about sleep disorders in spinal cord injured (SCI) patients. Three SCI patients who reported severe daytime sleepiness and sleep complaints were evaluated with nocturnal ...polysomnography and oxygen saturation with pulsoximeter on several occasions at home. In addition respiratory registration was preformed during overnight stay in the hospital. Two patients who had sleep apnoea episodes with reduced oxygen saturation during sleep were treated with continuous positive airway pressure with good results on sleep architecture, oxygen saturation, and daytime sleepiness. One obese patient was advised to lose weight and to reduce smoking and alcohol consumption, and following this advice his sleep related problems were reduced with no further treatment necessary. It is suggested that SCI patients who complain about sleep related disorders should be appropriately screened, with inclusion of nocturnal polysomnography, oxygen saturation, and respiratory registration and, depending on the screening results, appropriate advice/treatment applied.
What kind of great power is China? The dominant analysis in the West is that Beijing is increasingly acting in a self-confident and even aggressive way pushing for its own demands and interests. With ...point of departure in a characteristic of China in the international system today, this article argues that developments in Chinese foreign and security policy in recent years also reflect an insecure, inward-looking and reactive China still struggling with how to handle its new international role and the new and complex challenges and rising expectations that come with it. Consequently, Chinese foreign and security policy is currently in a process of reconstruction to better fit China's new international role as well as the changed domestic conditions and demands. Beijing's different handling of the ongoing conflicts in Libya and Syria illustrates this process. Adapted from the source document.
What kind of great power is China? e dominant analysis in the West is that Beijing is increasingly acting in a self-con dent and even aggressive way pushing for its own demands and interests. With ...point of depar- ture in a characteristic of China in the international system today, this article argues that developments in Chinese foreign and security policy in recent years also re ect an insecure, inward-looking and reactive China still struggling with how to handle its new international role and the new and complex challenges and rising expectations that come with it. Consequently, Chinese foreign and security policy is currently in a process of reconstruction to better t China’s new international role as well as the changed domestic conditions and demands. Beijing’s di erent handling of the ongoing con icts in Libya and Syria illustrates this process.
What kind of great power is China? e dominant analysis in the West is that Beijing is increasingly acting in a self-con dent and even aggressive way pushing for its own demands and interests. With ...point of depar- ture in a characteristic of China in the international system today, this article argues that developments in Chinese foreign and security policy in recent years also re ect an insecure, inward-looking and reactive China still struggling with how to handle its new international role and the new and complex challenges and rising expectations that come with it. Consequently, Chinese foreign and security policy is currently in a process of reconstruction to better t China’s new international role as well as the changed domestic conditions and demands. Beijing’s di erent handling of the ongoing con icts in Libya and Syria illustrates this process.
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