A non-lethal stable isotope analysis of valued freshwater predatory fish using blood and fin tissues as alternatives to muscle tissue

by Lukáš Vejřík, Ivana Vejříková, Zuzana Sajdlová, Luboš Kočvara, Tomáš Kolařík, Daniel Bartoň, Tomáš Jůza, Petr Blabolil, Jiří Peterka, Martin Čech, Mojmír Vašek

Stable isotope analysis (SIA) is widely used to study trophic ecology and food webs in aquatic ecosystems. In the case of fish, muscle tissue is generally preferred for SIA, and the method is lethal in most cases. We tested whether blood and fin clips can be used as non-lethal alternatives to muscle tissue for examining the isotopic composition of two freshwater predatory fish, European catfish (Silurus glanis) and Northern pike (Esox lucius), species of high value for many freshwater systems as well as invasive species in many others. Blood samples from the caudal vein, anal fin clips, and dorsal muscle obtained by biopsy punch were collected from four catfish and pike populations (14–18 individuals per population). Subsequently, these samples were analyzed for δ¹³C and δ¹⁵N. The effects of alternative tissues, study site, and fish body mass on the isotopic offset were investigated. Both species showed a correlation between the isotopic offset and the tissue type, as well as the study site, but no significant relationship with the body mass. The isotopic offsets between tissues were used to calculate the conversion equations. The results demonstrated that both blood and fin clips are suitable and less invasive alternative to muscle in SIA studies focused on European catfish and Northern pike. Blood provided better correspondence to muscle isotope values. However, our results clearly demonstrated that isotopic offsets between tissues vary significantly among populations of the same species. Therefore, obtaining a muscle biopsy from several individuals in any population is advisable to gain initial insights and establish a possible population-specific inter-tissue conversion.

Implementation of the advanced HIV disease care package with point-of-care CD4 testing during tuberculosis case finding: A mixed-methods evaluation

by Tinne Gils, Mashaete Kamele, Thandanani Madonsela, Shannon Bosman, Thulani Ngubane, Philip Joseph, Klaus Reither, Moniek Bresser, Erika Vlieghe, Tom Decroo, Irene Ayakaka, Lutgarde Lynen, Alastair Van Heerden

During TB-case finding, we assessed the feasibility of implementing the advanced HIV disease (AHD) care package, including VISITECT CD4 Advanced Disease (VISITECT), a semiquantitative test to identify a CD4≤200cells/μl. Adult participants with tuberculosis symptoms, recruited near-facility in Lesotho and South-Africa between 2021–2022, were offered HIV testing (capillary blood), Xpert MTB/RIF and Ultra, and MGIT culture (sputum). People living with HIV (PLHIV) were offered VISITECT (venous blood) and Alere tuberculosis-lipoarabinomannan (AlereLAM, urine) testing. AHD was defined as a CD4≤200cells/μl on VISITECT or a positive tuberculosis test. A CD4≤200cells/μl on VISITECT triggered Immy cryptococcal antigen (Immy CrAg, plasma) testing. Participants were referred with test results. To evaluate feasibility, we assessed i) acceptability and ii) intervention delivery of point-of-care diagnostics among study staff using questionnaires and group discussions, iii) process compliance, and iv) early effectiveness (12-week survival and treatment status) in PLHIV. Predictors for 12-week survival were assessed with logistic regression. Thematic content analysis and triangulation were performed. Among PLHIV (N = 676, 48.6% of 1392 participants), 7.8% were newly diagnosed, 81.8% on ART, and 10.4% knew their HIV status but were not on ART. Among 676 PLHIV, 41.7% had AHD, 29.9% a CD4≤200cells/μl and 20.6% a tuberculosis diagnosis. Among 200 PLHIV tested with Immy CrAg, 4.0% were positive. The procedures were acceptable for study staff, despite intervention delivery challenges related to supply and the long procedural duration (median: 73 minutes). At 12 weeks, among 276 PLHIV with AHD and 328 without, 3.3% and 0.9% had died, 84.8% and 92.1% were alive and 12.0% and 7.0% had an unknown status, respectively. Neither AHD nor tuberculosis status were associated with survival. Implementing AHD care package diagnostics was feasible during tuberculosis-case finding. AHD was prevalent, and not associated with survival, which is likely explained by the low specificity of VISITECT. Challenges with CD4 testing and preventive treatment uptake require addressing.

Involvement of an IgE/Mast cell/B cell amplification loop in abdominal aortic aneurysm progression

by Alexia Loste, Marc Clément, Sandrine Delbosc, Kevin Guedj, Jean Sénémaud, Anh-Thu Gaston, Marion Morvan, Guillaume Even, Grégory Gautier, Alexander Eggel, Michel Arock, Emanuele Procopio, Catherine Deschildre, Liliane Louedec, Jean-Baptiste Michel, Lydia Deschamps, Yves Castier, Raphaël Coscas, Jean-Marc Alsac, Pierre Launay, Giuseppina Caligiuri, Antonino Nicoletti, Marie Le Borgne

Aims

IgE type immunoglobulins and their specific effector cells, mast cells (MCs), are associated with abdominal aortic aneurysm (AAA) progression. In parallel, immunoglobulin-producing B cells, organised in tertiary lymphoid organs (TLOs) within the aortic wall, have also been linked to aneurysmal progression. We aimed at investigating the potential role and mechanism linking local MCs, TLO B cells, and IgE production in aneurysmal progression.

Methods and results

Through histological assays conducted on human surgical samples from AAA patients, we uncovered that activated MCs were enriched at sites of unhealed haematomas, due to subclinical aortic wall fissuring, in close proximity to adventitial IgE+ TLO B cells. Remarkably, in vitro the IgEs deriving from these samples enhanced MC production of IL-4, a cytokine which favors IgE class-switching and production by B cells. Finally, the role of MCs in aneurysmal progression was further analysed in vivo in ApoE^-/- mice subjected to angiotensin II infusion aneurysm model, through MC-specific depletion after the establishment of dissecting aneurysms. MC-specific depletion improved intramural haematoma healing and reduced aneurysmal progression.

Conclusions

Our data suggest that MC located close to aortic wall fissures are activated by adventitial TLO B cell-produced IgEs and participate to their own activation by providing support for further IgE synthesis through IL-4 production. By preventing prompt repair of aortic subclinical fissures, such a runaway MC activation loop could precipitate aneurysmal progression, suggesting that MC-targeting treatments may represent an interesting adjunctive therapy for reducing AAA progression.

A comparative analysis of depressive-like behavior: Exploring sex-related differences and insights

by Ana Carolina Cavalcante Rodrigues, Caroline Vitória de Lima Moreira, Camila Carlos Prado, Luan Silvestro Bianchini Silva, Rafael Fernandes Costa, Adesina Paul Arikawe, Gustavo Rodrigues Pedrino, Elson Alves Costa, Osmar Nascimento Silva, Hamilton Barbosa Napolitano, Iranse Oliveira-Silva, James Oluwagbamigbe Fajemiroye

Profiling the variability related to the estrous cycle is essential for assessing depressive-like behavior and screening drugs. This study compares circulating plasma corticosterone levels [CORT] and behavioral alterations in mice exposed to sucrose preference, forced swimming, and tail suspension tests (SPT, FST, and TST, respectively). While SPT exposure did not significantly alter [CORT], FST and TST showed notable changes. Mice in the TST exhibited increased movement and decreased immobility time compared to FST, suggesting a lower likelihood of depressive-like behavior in male mice. Notably, during the proestrus phase, female mice displayed the highest tendency for depressive-like behavior and elevated [CORT], but similar response to antidepressants (imipramine and fluoxetine). The inherent stress of the FST and TST tasks appears to influence [CORT] as well as depressant and antidepressant effects. These comparisons provide valuable insights for further behavioral phenotyping, model sensitivity assessment, and deepen our neurobiological understanding of depression in the context of drug screening.

Dexrazoxane does not mitigate early vascular toxicity induced by doxorubicin in mice

by Matthias Bosman, Dustin N. Krüger, Kasper Favere, Guido R. Y. De Meyer, Constantijn Franssen, Emeline M. Van Craenenbroeck, Pieter-Jan Guns

Apart from cardiotoxicity, the chemotherapeutic agent doxorubicin (DOX) provokes acute and long-term vascular toxicity. Dexrazoxane (DEXRA) is an effective drug for treatment of DOX-induced cardiotoxicity, yet it remains currently unknown whether DEXRA prevents vascular toxicity associated with DOX. Accordingly, the present study aimed to evaluate the protective potential of DEXRA against DOX-related vascular toxicity in a previously-established in vivo and ex vivo model of vascular dysfunction induced by 16 hour (h) DOX exposure. Vascular function was evaluated in the thoracic aorta in organ baths, 16h after administration of DOX (4 mg/kg) or DOX with DEXRA (40 mg/kg) to male C57BL6/J mice. In parallel, vascular reactivity was evaluated after ex vivo incubation (16h) of murine aortic segments with DOX (1 μM) or DOX with DEXRA (10 μM). In both in vivo and ex vivo experiments, DOX impaired acetylcholine-stimulated endothelium-dependent vasodilation. In the ex vivo setting, DOX additionally attenuated phenylephrine-elicited vascular smooth muscle cell (VSMC) contraction. Importantly, DEXRA failed to prevent DOX-induced endothelial dysfunction and hypocontraction. Furthermore, RT-qPCR and Western blotting showed that DOX decreased the protein levels of topoisomerase-IIβ (TOP-IIβ), a key target of DEXRA, in the heart, but not in the aorta. Additionally, the effect of N-acetylcysteine (NAC, 10 μM), a reactive oxygen species (ROS) scavenger, was evaluated ex vivo. NAC did not prevent DOX-induced impairment of acetylcholine-stimulated vasodilation. In conclusion, our results show that DEXRA fails to prevent vascular toxicity resulting from 16h DOX treatment. This may relate to DOX provoking vascular toxicity in a ROS- and TOP-IIβ-independent way, at least in the evaluated acute setting. However, it is important to mention that these findings only apply to the acute (16h) treatment period, and further research is warranted to delineate the therapeutic potential of DEXRA against vascular toxicity associated with longer-term repetitive DOX dosing.

Using microbiological data to improve the use of antibiotics for respiratory tract infections: A protocol for an individual patient data meta-analysis

by Irene Boateng, Beth Stuart, Taeko Becque, Bruce Barrett, Jennifer Bostock, Robin Bruyndonckx, Lucy Carr-Knox, Emily J. Ciccone, Samuel Coenen, Mark Ebell, David Gillespie, Gail Hayward, Katarina Hedin, Kerenza Hood, Tin Man Mandy Lau, Paul Little, Dan Merenstein, Edgar Mulogo, Jose Ordóñez-Mena, Peter Muir, Kirsty Samuel, Nader Shaikh, Sharon Tonner, Alike W. van der Velden, Theo Verheij, Kay Wang, Alastair D. Hay, Nick Francis

Background

Resistance to antibiotics is rising and threatens future antibiotic effectiveness. ‘Antibiotic targeting’ ensures patients who may benefit from antibiotics receive them, while being safely withheld from those who may not. Point-of-care tests may assist with antibiotic targeting by allowing primary care clinicians to establish if symptomatic patients have a viral, bacterial, combined, or no infection. However, because organisms can be harmlessly carried, it is important to know if the presence of the virus/bacteria is related to the illness for which the patient is being assessed. One way to do this is to look for associations with more severe/prolonged symptoms and test results. Previous research to answer this question for acute respiratory tract infections has given conflicting results with studies has not having enough participants to provide statistical confidence.

Aim

To undertake a synthesis of IPD from both randomised controlled trials (RCTs) and observational cohort studies of respiratory tract infections (RTI) in order to investigate the prognostic value of microbiological data in addition to, or instead of, clinical symptoms and signs.

Methods

A systematic search of Cochrane Central Register of Controlled Trials, Ovid Medline and Ovid Embase will be carried out for studies of acute respiratory infection in primary care settings. The outcomes of interest are duration of disease, severity of disease, repeated consultation with new/worsening illness and complications requiring hospitalisation. Authors of eligible studies will be contacted to provide anonymised individual participant data. The data will be harmonised and aggregated. Multilevel regression analysis will be conducted to determine key outcome measures for different potential pathogens and whether these offer any additional information on prognosis beyond clinical symptoms and signs.

Trial registration

PROSPERO Registration number: CRD42023376769.

Association of biomarkers of enteric dysfunction, systemic inflammation, and growth hormone resistance with seroconversion to oral rotavirus vaccine: A lasso for inference approach

by Katayi Mwila-Kazimbaya, Samuel Bosomprah, Obvious Nchimunya Chilyabanyama, Caroline Cleopatra Chisenga, Mwelwa Chibuye, Natasha Makabilo Laban, Michelo Simuyandi, Bert Huffer Jr, Miren Iturriza-Gomara, Robert K. M. Choy, Roma Chilengi

Background

Rotavirus gastroenteritis remains a leading cause of morbidity and mortality despite the introduction of vaccines. Research shows there are several factors contributing to the reduced efficacy of rotavirus vaccines in low- and middle-income settings. Proposed factors include environmental enteric dysfunction (EED), malnutrition, and immune dysfunction. This study aimed to assess the effect of these factors on vaccine responses using a machine learning lasso approach.

Methods

Serum samples from two rotavirus clinical trials (CVIA 066 n = 99 and CVIA 061 n = 124) were assessed for 11 analytes using the novel Micronutrient and EED Assessment Tool (MEEDAT) multiplex ELISA. Immune responses to oral rotavirus vaccines (Rotarix, Rotavac, and Rotavac 5D) as well as a parenteral rotavirus vaccine (trivalent P2-VP8) were also measured and machine learning using the lasso approach was then applied to investigate any associations between immune responses and environmental enteric dysfunction, systemic inflammation, and growth hormone resistance biomarkers.

Results

Both oral and parenteral rotavirus vaccine responses were negatively associated with retinol binding protein 4 (RBP4), albeit only weakly for oral vaccines. The parenteral vaccine responses were positively associated with thyroglobulin (Tg) and histidine-rich protein 2 (HRP2) for all three serotypes (P8, P6 and P4), whilst intestinal fatty acid binding protein (I-FABP) was negatively associated with P6 and P4, but not P8, and soluble transferrin receptor (sTfR) was positively associated with P6 only.

Conclusion

MEEDAT successfully measured biomarkers of growth, systemic inflammation, and EED in infants undergoing vaccination, with RBP4 being the only analyte associated with both oral and parenteral rotavirus vaccine responses. Tg and HRP2 were associated with responses to all three serotypes in the parenteral vaccine, while I-FABP and sTfR results indicated possible strain specific immune responses to parenteral immunization.