Amoebic gill disease (AGD) is a pathogenic disease in salmonids caused by Neoparamoeba perurans. Treatment of AGD infection has been through freshwater bathing of the fish. However, as the ...availability of fresh water is often limited, hydrogen peroxide has been introduced as an alternative treatment. This study investigated the effect of hydrogen peroxide as treatment for AGD‐infected salmon (Salmo salar L.,) at different seawater temperatures and hydrogen peroxide dosages. In total, 600 fish were challenged with N. perurans and the severity of the AGD infection was measured using a gill score scale. After challenge and disease development, the fish were distributed into 12 tanks. The treatment was performed at different seawater temperatures (8°C, 12°C, 17°C) using different hydrogen peroxide doses. Each temperature included an untreated control group. Linear models were used to analyse gill score. A significant effect of treatment was found (−0.68 ± 0.05) regardless of dose and temperature, suggesting that hydrogen peroxide was effective in treating AGD. When the model included dose, a negative linear relationship between dose and gill score was found. The study proved that treatment of AGD with hydrogen peroxide was successful, as gills partially recovered following treatment and further disease development was delayed.
•Responses to vaccination were examined in salmon head kidney during five weeks.•Transcriptome analyses showed shift in character of inflammation after two weeks.•This coincided with B cells ...differentiation and increase of nonspecific antibodies.•Antibodies to bacterial antigens delivered with vaccine appeared one week later.•Antibodies responses were mirrored with changes in repertoire of IgM transcripts.
The majority of studies of vaccine responses in Atlantic salmon have focused on several weeks after vaccination, and employed a limited number of marker genes. In this study, novel techniques were used to examine a broad panel of expressed genes and antibody repertoire of Atlantic salmon following vaccination. Salmon parr were vaccinated with a multivalent oil-based vaccine, and blood plasma and head kidney were sampled at several time-points between 0–35 days post vaccination. Saline-injected fish were used as control at all time-points. Microarray analyses showed increased expression of immune genes from the first day to the end of study in the head kidney of vaccinated fish. Genes up-regulated in the late phase included several leukocyte markers and components of the oxidative burst complex. A suite of genes that can take part in B cells differentiation were up-regulated from day 14, at which time secretory IgM transcripts also peaked. This coincided with marked increased plasma titres of non-vaccine specific antibodies binding to a hapten-carrier antigen DNP-KLH, while antibodies to bacterial components of the vaccine, Moritella viscosa and Aeromonas salmonicida, first showed significantly elevated antibody levels at day 21, and at a markedly lower magnitude than the non-vaccine specific titres. Sequencing of the variable region of IgM heavy chain (CDR3) revealed higher cumulative frequencies of unique clonotypes in vaccinated salmon starting from day 14 when specific antibodies were first detected. Reduced sequence variance of CDR3 suggested expansion of recently emerged clonotypes. Overall, the results presented here follow a broad panel of gene expression, immunoglobulin sequencing and plasma antibody titres in the first few weeks after vaccination of Atlantic salmon, pointing to a potentially important contribution of non-vaccine specific antibody responses early in the vaccine response.
Bullying victimization is directly associated with a wide array of longstanding psychological problems (e.g., Takizawa Maughan, & Arseneault, 2014; Vaillancourt et al., 2013). Nevertheless, few ...comprehensive victim-tailored interventions exist that explicitly target the negative impact of bullying. Evidence from both neurobiological and psychological research suggests that victims experience bullying as trauma; therefore, treating the distress associated with bullying victimization using trauma-focused intervention may be beneficial. The purposes of this randomized controlled trial were to: (a)test an internet-delivered, therapist-guided (i.e., therapist monitored client progress through the treatment modules and provided feedback and support through secure e-mail messaging) and content-modified (i.e., to fit the experience of bullying victimization) version of cognitive processing therapy (CPT) for the psychological distress associated with bullying victimization, and (b) to examine risk and protective factors in the pathways from bullying victimization to psychological adjustment. The sample comprised 52 adults who self-identified as victims of bullying. Participants were randomized into internet-delivered CPT, an active control group of internet-delivered stress management (SM), or a waitlist. Treatment outcomes included maladaptive appraisals, symptoms of posttraumatic stress disorder (PTSD), depression, anxiety, anger, and related latent constructs (e.g., distress tolerance). Secondary measures examining risk and protective factors included assessment of coping styles, social support, and resilience. Treatment outcome and secondary measures were administered pre-treatment, post-treatment, and at one-month follow-up. Symptoms of depression, anxiety, and anger were, further, monitored with weekly measures. Hierarchical linear modeling and multiple regressions were used to analyse the data. Results indicated that CPT was effective in reducing maladaptive self-appraisals related to bullying victimization and symptoms of PTSD compared to the waitlist and SM, whereas SM outperformed CPT and the waitlist in reducing general psychological distress. Event centrality (i.e., the extent to which an experience has become central to identity and understanding of the world) led to stronger maladaptive appraisals for participants with a tendency to engage in catastrophizing. Number of reported lifetime bullying victimization experiences and anger also predicted stronger maladaptive appraisals. The overall findings of this trial suggest that internet-delivered CPT is effective for the psychological distress and maladaptive appraisals associated with bullying victimization, but adaptions might be needed to target more effectively symptoms of general distress and latent constructs related to anxiety and depression.
Introduction
Le temps passé devant un écran, une mesure des comportements sédentaires,
s’est révélé être un déterminant essentiel de la santé chez les jeunes dans les sociétés
contemporaines, où la ...majorité des dimensions de leur vie comprennent l’accès à un
écran. Une approche peu étudiée pour réduire le temps passé devant un écran chez les
jeunes est son association avec la réduction de l’intimidation. Cette étude vise à comprendre
le lien entre la perpétration de l’intimidation, la victimisation, la perception des jeunes
à l’égard du milieu scolaire et divers comportements associés au temps passé devant un
écran.
Méthodologie
Un total de 44 861 jeunes de 13 à 18 ans ont répondu, dans deux provinces
canadiennes, à un questionnaire validé recueillant des données autodéclarées sur
les comportements de santé et leurs effets, notamment divers comportements associés au
temps passé devant un écran, la perpétration de l’intimidation, la victimisation et le sentiment
d’appartenance à l’école. Les variables à l’étude étaient le temps total passé devant
un écran et celui passé spécifiquement à regarder la télévision, à jouer à des jeux vidéo, à
naviguer sur Internet ainsi que celui consacré à des comportements en lien avec la communication.
Les modèles finaux ont été élaborés avec PROC MIXED dans SAS 9.4 à l’aide
d’une modélisation à valeur aléatoire. Ils ont été ajustés selon l’âge, l’origine ethnique, le
revenu hebdomadaire disponible, les heures de clarté et les variables météorologiques.
Résultats
Comparativement aux jeunes n’ayant signalé aucune participation à
l’intimidation, les jeunes qui s’étaient livrés à des actes d’intimidation, les jeunes victimes
d’intimidation et les jeunes ayant été à la fois intimidateurs et victimes d’intimidation
passaient en moyenne plus de minutes par jour devant un écran toutes catégories de
temps d’écran confondues. Les jeunes qui ont déclaré être heureux et se sentir en sécurité
à l’école et qui considéraient leurs enseignants comme justes présentaient des niveaux
moins élevés pour divers comportements associés au temps passé devant un écran.
Conclusion
Puisqu’une forte corrélation négative a été observée entre la non-participation
à l’intimidation et divers comportements associés au temps passé devant un écran, les
politiques scolaires visant à accroître le sentiment d’appartenance à l’école pour lutter
contre l’intimidation et réduire le temps passé devant un écran pourraient offrir une
approche novatrice de réduction de ces comportements néfastes.
We have recently sequenced the genome of a novel thermophilic bacteriophage designated as TS2126 that infects the thermophilic eubacterium Thermus scotoductus. One of the annotated open reading ...frames (ORFs) shows homology to T4 RNA ligase 1, an enzyme of great importance in molecular biology, owing to its ability to ligate single-stranded nucleic acids. The ORF was cloned, and recombinant protein was expressed, purified and characterized. The recombinant enzyme ligates single-stranded nucleic acids in an ATP-dependent manner and is moderately thermostable. The recombinant enzyme exhibits extremely high activity and high ligation efficiency. It can be used for various molecular biology applications including RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE). The TS2126 RNA ligase catalyzed both inter- and intra-molecular single-stranded DNA ligation to >50% completion in a matter of hours at an elevated temperature, although favoring intra-molecular ligation on RNA and single-stranded DNA substrates. The properties of TS2126 RNA ligase 1 makes it very attractive for processes like adaptor ligation, and single-stranded solid phase gene synthesis.
Phage vB_Tsc2631 infects the extremophilic bacterium Thermus scotoductus MAT2631 and uses the Ts2631 endolysin for the release of its progeny. The Ts2631 endolysin is the first endolysin from ...thermophilic bacteriophage with an experimentally validated catalytic site. In silico analysis and computational modelling of the Ts2631 endolysin structure revealed a conserved Zn2+ binding site (His30, Tyr58, His131 and Cys139) similar to Zn2+ binding site of eukaryotic peptidoglycan recognition proteins (PGRPs). We have shown that the Ts2631 endolysin lytic activity is dependent on divalent metal ions (Zn2+ and Ca2+). The Ts2631 endolysin substitution variants H30N, Y58F, H131N and C139S dramatically lost their antimicrobial activity, providing evidence for the role of the aforementioned residues in the lytic activity of the enzyme. The enzyme has proven to be not only thermoresistant, retaining 64.8% of its initial activity after 2 h at 95 degree C, but also highly thermodynamically stable (Tm = 99.82 degree C, delta Hcal = 4.58 104 cal mol-1). Substitutions of histidine residues (H30N and H131N) and a cysteine residue (C139S) resulted in variants aggregating at temperatures greater than or equal to 75 degree C, indicating a significant role of these residues in enzyme thermostability. The substrate spectrum of the Ts2631 endolysin included extremophiles of the genus Thermus but also Gram-negative mesophiles, such as Escherichia coli, Salmonella panama, Pseudomonas fluorescens and Serratia marcescens. The broad substrate spectrum and high thermostability of this endolysin makes it a good candidate for use as an antimicrobial agent to combat Gram-negative pathogens.
Dietary fish oil is believed to have a beneficial effect in various infections and in autoimmune disorders. This effect may correspond to an altered immune response. In order to discover whether the ...effect of dietary fish oil is different in various infections, we studied the survival of mice fed fish oil or corn oil supplemented diets and infected in the lungs with either Klebsiella pneumoniae or Streptococcus pneumoniae. 120 NMRI mice were divided into 4 groups, of which 2 groups were fed a fish oil supplemented diet and 2 a corn oil supplemented diet. After 6 weeks the mice were infected in the lungs with Klebsiella pneumoniae (fish oil groups and corn oil groups) or with Streptococcus pneumoniae serotype 3 (both groups). The survival rate was monitored. The experiment was performed twice. The survival of the mice fed fish oil enriched diet and infected with Klebsiella pneumoniae was significantly better compared with the mice fed corn oil enriched diet (p=0.0001 and p=0.0013). No difference was found between the mice fed corn oil enriched diet or fish oil enriched diet and infected with Streptococcus pneumoniae serotype 3 (p=0.74 and p=0.15). Our results indicate that dietary fish oil has a beneficial effect on survival of mice after experimental pneumoniae when infected with Klebsiella pneumoniae, but not after infection with Streptococcus pneumoniae serotype 3.
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