A study of the serological response to helminths in domestic animals

A study has "been made of the serological responses occurring in domestic animals as a result of natural infestation with helminth parasites. The helminth infestations studied were those of Fasclola hepatica. Cysticereus bovls. Ascaris lumhrlcoides, Dlctyocaulua vlviparus and Trichlnella spiralis,F.HEPATLCA. The serological response, as indicated by the precipitin test, in F.hepatlca infestation was most marked when the immature parasites were in their migratory phase. Thereafter the precipitin antibody level became lowerSpecific complement fixation antibodies were demonstrated in the sera of only one infested animal. This was indicative that the complement fixation technique was unsuitable for the demonstrat¬ ion of antibodies in P,hepatica infestation. Alcoholic extracts of the parasite were found to give varying degrees of r.on specific complement fixation with sheep sera, irrespective of F.hepatica infestation.The miracidia of F.hepatlca were observed to suffer a lethal effect when placed in sheep serum. Complement was necessary for the reaction.Hypersensitivity, demonstrable by an JLOD# Intradermal test, was evident in a large percentage of animals infested with F.hepatica. In some cases this hypersensitivity was passively transferable, "by means of serum, to a non sensitive animal. Local skin desensitisation could "be produced to a marked degree hut generalised skin desensitisation was less obvious when large quantities of antigenic material were administered.G.BOVIS. Precipitin antibodies were demonstrated in the sera of animals which showed multiple eysticerci in the musculature. When only a few (1 or 2) eysticerci were present a serological response was frequently absent. Polysaccharide solutions of the parent parasite, T# saglnata# produced precipitin reactions with the sera of animals infested with P.hepatica only. This was thought to be due to an isoagglutinin like producing antigen present in both T.saginata and hepatlca.Animals infested with F#hepatica produced hypersensitive skin reactions to extracts of C.bovls# A common allergen In the two parasites was thought to be responsible#A.LUMBRIOOIDEA. Precipitin antibodies were demonstrated in the sera of pigs. These were found to bear no relationship to the presence of mature A.lumbricoides In the intestine# They did, however, show a relationship to the degree of chronic focal interstitial hepatitis.Hypersensitivity to extracts of A.lumbricoldes was evident in the majority of swine. This was similar to the precipitin reaction, in that it was related to the degree of chronic focal interstitial hepatitis but not to the presence of intestinal forms of A.lumbrlcolfles.D.VIVLNARUS. The majority of cattle examined showed skin hypersensitivity to D.vivlparue extracts. This hypersensitivity was most evident in the age group 2-j? to 3-j years. The hypersensitivity demonstrated occurred in the absence of parasites. Intestinal helminths did not influence the hypersensitive state.Hypersensitivity was demonstrated in sheep undergoing a sub-clinical infestation with 13.filaria Infestations with other lung worms produced a hypersensitive state which could be demonstrated by D.filaria extracts. This was indicative of a group reaction.T,SPIRALIS. Hypersensitivity to extracts of T.spiralis was demonstrated in only 5# 4$ of swine. Only 0.91 of swine showed marked reactions. Since these occurred in animals possessing marked hypersensitivity to A.lumbrlcoidea it was concluded that a strong hypt rsensitivity to A,lmribrlcoltl.es could sensitise pigs to extracts of T.spiralis. Infestations with T.trlchiura did not produce hypersensitivity to T.spiralis extracts.The use of animals at an abattoir afforded the opportunity to correlate the serological findings with post mortem evidence of infestation. Since the lack of helminth eggs in the faeces does not necessarily indicate absence of helminth infestation the post mortem examinations carried out gave a more complete picture of the parasitic burden. As a result it was found that light infestations or pathological evidence of helminth infestation could be correlated with the serological findings (vide P.hepatica. C.bovls and A.lumbrlcoldes). If faeces examination had been the sole criterion of evidence of infestation no correlation between serological findings and infestation would have been evident and false conclusions may have been drawn

Integration of juvenile habitat quality and river connectivity models to understand and prioritise the management of barriers for Atlantic salmon populations across spatial scales

Thanks to the Scottish Government Hydro Nation Scholarship programme for funding WBB. Authors from Marine Scotland Science Freshwater Fisheries Laboratories delivered this work through Service Level Agreement FW02G. Some map features are based on digital spatial data licensed from CEH, NERC© Crown Copyright and database right (2018), all rights reserved. Ordnance Survey License number 100024655. Catchment boundaries were from SEPA (2009). The Obstacles to Fish Migration dataset is from SEPA. The authors thank the two anonymous referees for their feedback on the manuscript.Peer reviewedPostprin

Supporting researchers conducting qualitative research into sensitive, challenging, and difficult topics: Experiences and practical applications.

Qualitative researchers often engage in work addressing challenging, difficult, or sensitive topics and are consequently exposed to the participants’ narratives which may be emotionally charged, distressing, or compromising. These narratives occasionally rest heavy on a researcher’s conscience or may linger in the mind. Much literature has assessed how best to keep participants safe, but less attention has been given to how we keep researchers safe. We therefore document the following: (1) Our experiences of the issues presented by undertaking qualitative research involving challenging, difficult, or sensitive topics; and (2) Practical principles devised to overcome these issues, ensuring safety and wellbeing amongst researchers engaging in these types of qualitative research. We provide guidance for qualitative researchers of all levels of experience and expertise on how best to protect and support themselves, their colleagues, and other collaborating research staff, when undertaking qualitative research which might otherwise feel uncomfortable or overwhelming to tackle

Sensitive, Challenging, and Difficult Topics: Experiences and Practical Considerations for Qualitative Researchers

Qualitative researchers often engage in work addressing challenging, difficult, or sensitive topics and are consequently exposed to the participants’ narratives which may be emotionally charged, distressing, or compromising. These narratives occasionally rest heavy on a researcher’s conscience or may linger in the mind. Much literature has assessed how best to keep participants safe, but less attention has been given to how we keep researchers safe. We therefore document the following: (1) Our experiences of the issues presented by undertaking qualitative research involving challenging, difficult, or sensitive topics; and (2) Practical principles devised to overcome these issues, ensuring safety and wellbeing amongst researchers engaging in these types of qualitative research. We provide guidance for qualitative researchers of all levels of experience and expertise on how best to protect and support themselves, their colleagues, and other collaborating research staff, when undertaking qualitative research which might otherwise feel uncomfortable or overwhelming to tackle

Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders