Prospecting the insect model, Galleria mellonella, for gut-related pathobiology

Animal research has contributed immensely to medical and scientific advances over the last century, and continues to play important roles in enhancing our understanding of infectious and non-communicable disease development, and the search for treatments. The mouse, for example, shares ~95% of human genes and is the most widespread vertebrate model in use. Since the late 1980s, there has been several UK and EU directives (e.g., 2010/63/EU) to improve the welfare of animals considered essential for experimentation, and to link directly with the principle of the 3Rs, to Replace, Reduce and Refine animal use. Additionally, animal maintenance, husbandry, compliance with legislation and licencing, and staff training are costly and time-consuming. Hence, there is much to gain from developing alternative in vivo models and complementary in vitro, in chemico and in silico tools. Larvae of the wax moth Galleria mellonella represent one such surrogate to rodents, and have been used successfully to study microbial isolates for virulence traits, putative antibiotic therapies, and more recently, toxicological assessment. There is an abundance of practical and biological advantages to selecting G. mellonella over rodents and traditional non-mammalian fruit flies and nematodes (which are described in Chapter 1), but one area lacking in knowledge is their applicability for studies of gut pathobiology. Therefore, the aim of this thesis was to evaluate the usefulness and accuracy of G. mellonella larvae as a model for gut specific toxins and pathogens when administered through an oral route (gavage). A series of whole-organism (phenotype), cellular, biochemical, microbiological and microscopy methods were used to interrogate the gastrointestinal tract of G. mellonella in the absence and presence of chemicals and microbes known to cause gastropathy in rodents and humans. First, the transferability of the indomethacin restraint/ulcer assay was established in G. mellonella, with levels of tissue deterioration and enhanced leakiness reminiscent of rodents (Chapter 2). Second, the rearing of insects on nutraceuticals Cordyceps sinensis and bovine colostrum alleviated gut damage caused by indomethacin, and improved survival outcomes when challenged with the enteric pathogen Campylobacter jejuni (Chapter 3). Third, oral administration of shellfish poisoning toxins (okadaic acid and azaspiracids 1-3) to G. mellonella, interfered with tissue integrity and microbial stability of the gastrointestinal tract, and produced comparable LD50 levels to their rodent counterparts (Chapter 4). The results presented here go beyond establishing synonymous damage phenomena between G. mellonella larvae and vertebrates (Chapter 5), but adds new knowledge to the structure and function of the lepidopteran alimentary canal, the cytopathology of emerging marine toxins, and how diet invariably influences a host’s capacity to recover from subacute chemical and microbial disruptors

The diarrhetic shellfish-poisoning toxin, okadaic acid, provokes gastropathy, dysbiosis and susceptibility to bacterial infection in a non-rodent bioassay, Galleria mellonella

Diarrhetic shellfish-poisoning (DSP) toxins such as okadaic acid and dinophysistoxins harm the human gastrointestinal tract, and therefore, their levels are regulated to an upper limit of 160 μg per kg tissue to protect consumers. Rodents are used routinely for risk assessment and studies concerning mechanisms of toxicity, but there is a general move toward reducing and replacing vertebrates for these bioassays. We have adopted insect larvae of the wax moth Galleria mellonella as a surrogate toxicology model. We treated larvae with environmentally relevant doses of okadaic acid (80–400 μg/kg) via intrahaemocoelic injection or gavage to determine marine toxin-related health decline: (1) whether pre-exposure to a sub-lethal dose of toxin (80 μg/kg) enhances susceptibility to bacterial infection, or (2) alters tissue pathology and bacterial community (microbiome) composition of the midgut. A sub-lethal dose of okadaic acid (80 μg/kg) followed 24 h later by bacterial inoculation (2 × 105 Escherichia coli) reduced larval survival levels to 47%, when compared to toxin (90%) or microbial challenge (73%) alone. Histological analysis of the midgut depicted varying levels of tissue disruption, including nuclear aberrations associated with cell death (karyorrhexis, pyknosis), loss of organ architecture, and gross epithelial displacement into the lumen. Moreover, okadaic acid presence in the midgut coincided with a shift in the resident bacterial population over time in that substantial reductions in diversity (Shannon) and richness (Chao-1) indices were observed at 240 μg toxin per kg. Okadaic acid-induced deterioration of the insect alimentary canal resembles those changes reported for rodent bioassays

Accelerated versus standard epirubicin followed by cyclophosphamide, methotrexate, and fluorouracil or capecitabine as adjuvant therapy for breast cancer (UK TACT2; CRUK/05/19): quality of life results from a multicentre, phase 3, open-label, randomised, controlled trial

BACKGROUND: Adjuvant chemotherapy for patients with early breast cancer improves outcomes but its toxicity affects patients' quality of life (QOL). The UK TACT2 trial investigated whether accelerated epirubicin improves time to recurrence and if oral capecitabine is non-inferior to cyclophosphamide, methotrexate, and fluorouracil (CMF) for efficacy with less toxicity. Results showed no benefit for accelerated epirubicin and capecitabine was non-inferior. As part of the QOL substudy, we aimed to assess the effect of chemotherapies on psychological distress, physical symptoms, and functional domains. METHODS: TACT2 was a multicentre, phase 3, open-label, parallel-group, randomised, controlled trial done in 129 UK centres. Participants were aged 18 years or older with histologically confirmed node-positive or high-risk node-negative invasive primary breast cancer, who had undergone complete excision, and due to receive adjuvant chemotherapy. Patients were randomly assigned (1:1:1:1) to four cycles of 100 mg/m2 epirubicin either every 3 weeks (standard epirubicin) or every 2 weeks with 6 mg pegfilgrastim on day 2 of each cycle (accelerated epirubicin), followed by four 4-week cycles of either CMF (600 mg/m2 cyclophosphamide intravenously on days 1 and 8 or 100 mg/m2 orally on days 1–14; 40 mg/m2 methotrexate intravenously on days 1 and 8; and 600 mg/m2 fluorouracil intravenously on days 1 and 8 of each cycle) or four 3-week cycles of 2500 mg/m2 capecitabine (1250 mg/m2 given twice daily on days 1–14 of each cycle). The randomisation schedule was computer generated in random permuted blocks, stratified by centre, number of nodes involved (none vs 1–3 vs ≥4), age (≤50 years vs >50 years), and planned endocrine treatment (yes vs no). QOL was one of the secondary outcomes and is reported here. All patients from a subset of 44 centres were invited to complete QOL questionnaires (Hospital Anxiety and Depression Scale [HADS] and European Organisation for Research and Treatment of Cancer [EORTC] Quality of Life Questionnaire 30-item core module [QLQ-C30] and Quality of Life Questionnaire breast module [QLQ-BR23]) at baseline, end of standard or accelerated epirubicin, end of CMF or capecitabine, and at 12 and 24 months after randomisation. The QOL substudy prespecified two coprimary QOL outcomes assessed in the intention-to-treat population: overall QOL (reported elsewhere) and HADS total score. Prespecified secondary QOL outcomes were EORTC QLQ-C30 subscales of physical function, role function, and fatigue and EORTC QLQ-BR23 subscales of sexual function and systemic therapy side-effects. This trial is registered with ISRCTN, ISRCTN68068041, and ClinicalTrials.gov, NCT00301925. FINDINGS: From Dec 16, 2005, to Dec 5, 2008, 4391 patients (20 [0·5%] of whom were male) were enrolled in TACT2; 1281 (85·8%) of 1493 eligible patients were included in the QOL substudy. Eight (0·6%) participants in the QOL substudy were male and 1273 (99·4%) were female. Median follow-up was 85·6 months (IQR 80·6–95·9). Analysis was performed on the complete QOL dataset (as of Sept 15, 2011) when all participants had passed the 24-month timepoint. Prerandomisation questionnaires were completed by 1172 (91·5%) patients and 1179 (92·0%) completed at least one postrandomisation questionnaire. End-of-treatment HADS depression score (p=0·0048) and HADS total change score (p=0·0093) were worse for CMF versus capecitabine. Accelerated epirubicin led to worse physical function (p=0·0065), role function (p<0·0001), fatigue (p=0·0002), and systemic side-effects (p=0·0001), but not sexual function (p=0·36), compared with standard epirubicin during treatment, but the effect did not persist. Worse physical function (p=0·0048), sexual function (p=0·0053), fatigue (p<0·0001), and systemic side-effects (p<0·0001), but not role functioning (p=0·013), were seen for CMF versus capecitabine at end of treatment; these differences persisted at 12 months and 24 months. INTERPRETATION: Accelerated epirubicin was associated with worse QOL than was standard epirubicin but only during treatment. These findings will help patients and clinicians make an informed choice about accelerated chemotherapy. CMF had worse QOL effects than did capecitabine, which were persistent for 24 months. The favourable capecitabine QOL compared with CMF supports its use as an adjuvant option after neoadjuvant chemotherapy in patients with triple-negative breast cancer

How many metazoan species live in the world’s largest mineral exploration region?

The global surge in demand for metals such as cobalt and nickel has created unprecedented interest in deep-sea habitats with mineral resources. The largest area of activity is a 6 million km2 region known as the Clarion-Clipperton Zone (CCZ) in the central and eastern Pacific, regulated by the International Seabed Authority (ISA). Baseline biodiversity knowledge of the region is crucial to effective management of environmental impact from potential deep-sea mining activities, but until recently this has been almost completely lacking. The rapid growth in taxonomic outputs and data availability for the region over the last decade has allowed us to conduct the first comprehensive synthesis of CCZ benthic metazoan biodiversity for all faunal size classes. Here we present the CCZ Checklist, a biodiversity inventory of benthic metazoa vital to future assessments of environmental impacts. An estimated 92% of species identified from the CCZ are new to science (436 named species from a total of 5,578 recorded). This is likely to be an overestimate owing to synonyms in the data but is supported by analysis of recent taxonomic studies suggesting that 88% of species sampled in the region are undescribed. Species richness estimators place total CCZ metazoan benthic diversity at 6,233 (+/−82 SE) species for Chao1, and 7,620 (+/−132 SE) species for Chao2, most likely representing lower bounds of diversity in the region. Although uncertainty in estimates is high, regional syntheses become increasingly possible as comparable datasets accumulate. These will be vital to understanding ecological processes and risks of biodiversity loss

The GOLMePsA study protocol: an investigator-initiated, double-blind, parallel-group, randomised, controlled trial of GOLimumab and methotrexate versus methotrexate in early diagnosed psoriatic arthritis using clinical and whole body MRI outcomes

Background: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis which impacts significantly on the quality of life and work capacity of affected individuals. Recent evidence has shown that early control of inflammation in PsA leads to improved long-term outcomes. It is postulated that prompt intervention after diagnosis using a remission-induction treatment strategy will lead to improved outcomes and optimal disease control of PsA. The aim of the present study was to compare the clinical efficacy of a treatment strategy in newly diagnosed, treatment naïve PsA subjects, using the combination of golimumab (GOL), methotrexate (MTX) and steroids versus standard care (MTX monotherapy plus steroids). Methods/design: GOLMePsA is an investigator initiated, phase IIIb, single-centre, randomised, double-blind, placebo-controlled, two-armed, parallel-group, imaging-supplemented study. Eighty-eight PsA patients, diagnosed within 24 months prior to screening and treatment naïve, will be randomised at baseline to receive: (arm 1) the combination of intramuscular/intra-articular prednisolone, MTX and GOL or (arm 2) the combination of intramuscular/intra-articular prednisolone, MTX and placebo for 24 weeks (interventional period). Primary outcome measure is clinical improvement (at least 1 unit difference) in the Psoriatic ArthritiS Disease Activity Score (PASDAS) composite index. Reflecting a “step down” therapeutic approach, all participants successfully completing the interventional period will be followed up for a further 28 weeks. During this observational period, stable maintenance MTX monotherapy will continue for both arms, unless in case of intolerance or PsA relapse. In the latter case, additional treatment will be provided. Overall, the GOLMePsA study length is planned to be 52 weeks. Discussion: The hypothesis underlining this study is that very early treatment with first-line GOL reduces disease activity in PsA, in comparison to conventional therapy. Trial registration: EudraCT 2013–004122-28. 24/09/2013

Did the UK's public health Shielding policy protect the clinically extremely vulnerable during the Covid-19 pandemic in Wales? Results of EVITE Immunity, a link data retrospective study

Introduction The UK shielding policy intended to protect people at highest risk of harm from COVID-19 infection. We aimed to describe intervention effects in Wales at 1 year. Methods Retrospective comparison of linked demographic and clinical data for cohorts comprising people identified for shielding from 23rd March to 21st May 2020; and the rest of the population. Health records were extracted with event dates between 23rd March 2020 and 22nd March 2021 for the comparator cohort and from the date of inclusion until one year later for the shielded cohort. Results The shielded cohort included 117,415 people, with 3,086,385 in the comparator cohort. The largest clinical categories in the shielded cohort were severe respiratory condition (35.5%), immunosuppressive therapy (25.9%) and cancer (18.6%). People in the shielded cohort were more likely to be female, aged >= 50, living in relatively deprived areas, care home residents and frail. The proportion of people tested for COVID-19 was higher in the shielded cohort (OR 1.616; 95% CI 1.597 -1.637), with lower positivity rate IRR 0.716 (95% CI 0.697 – 0.736). The known infection rate was higher in the shielded cohort (5.9% versus 5.7%). People in the shielded cohort were more likely to die (OR 3.683; 95% CI: 3.583 – 3.786); have a critical care admission (OR 3.339; 95% CI: 3.111 – 3.583), hospital emergency admission (OR 2.883; 95% CI: 2.837 – 2.930), Emergency Department attendance (OR 1.893; 95% CI: 1.867 – 1.919) and Common Mental Disorder (OR 1.762; 95% CI: 1.735 – 1.789). Conclusion Deaths and healthcare utilisation were higher amongst shielded people than the general population, as would be expected in the sicker population. Differences in testing rates, deprivation and pre-existing health are potential confounders, however lack of clear impact on infection rates raises questions about the success of shielding and indicates that further research is required to fully evaluate this national policy intervention

Perspectives and Experiences of Patient-Led Melanoma Surveillance Using Digital Technologies From Clinicians Involved in the MEL-SELF Pilot Randomized Controlled Trial: Qualitative Interview Study

The growing number of melanoma patients who need long-term surveillance increasingly exceeds the capacity of the dermatology workforce, particularly outside of metropolitan areas. Digital technologies that enable patients to perform skin self-examination and send dermoscopic images of lesions of concern to a dermatologist (mobile teledermoscopy) are a potential solution. If these technologies and the remote delivery of melanoma surveillance are to be incorporated into routine clinical practice, they need to be accepted by clinicians providing melanoma care, such as dermatologists and general practitioners (GPs). Objective: This study aimed to explore perceptions of potential benefits and harms of mobile teledermoscopy, as well as experiences with this technology, among clinicians participating in a pilot randomized controlled trial (RCT) of patient-led melanoma surveillance. Methods: This qualitative study was nested within a pilot RCT conducted at dermatologist and skin specialist GP–led melanoma clinics in New South Wales, Australia. We conducted semistructured interviews with 8 of the total 11 clinicians who were involved in the trial, including 4 dermatologists (3 provided teledermatology, 2 were treating clinicians), 1 surgical oncologist, and 3 GPs with qualifications in skin cancer screening (the remaining 3 GPs declined an interview). Thematic analysis was used to analyze the data with reference to the concepts of “medical overuse” and “high-value care.