Paediatric meningitis in the conjugate vaccine era and a novel clinical decision model to predict bacterial aetiology

OBJECTIVES

The aims of this study were to assess aetiology and clinical characteristics in childhood meningitis, and develop clinical decision rules to distinguish bacterial meningitis from other similar clinical syndromes.

METHODS

Children aged <16 years hospitalised with suspected meningitis/encephalitis were included, and prospectively recruited at 31 UK hospitals. Meningitis was defined as identification of bacteria/viruses from cerebrospinal fluid (CSF) and/or a raised CSF white blood cell count. New clinical decision rules were developed to distinguish bacterial from viral meningitis and those of alternative aetiology.

RESULTS

The cohort included 3002 children (median age 2·4 months); 1101/3002 (36·7%) had meningitis, including 180 bacterial, 423 viral and 280 with no pathogen identified. Enterovirus was the most common pathogen in those aged <6 months and 10-16 years, with Neisseria meningitidis and/or Streptococcus pneumoniae commonest at age 6 months to 9 years. The Bacterial Meningitis Score had a negative predictive value of 95·3%. We developed two clinical decision rules, that could be used either before (sensitivity 82%, specificity 71%) or after lumbar puncture (sensitivity 84%, specificity 93%), to determine risk of bacterial meningitis.

CONCLUSIONS

Bacterial meningitis comprised 6% of children with suspected meningitis/encephalitis. Our clinical decision rules provide potential novel approaches to assist with identifying children with bacterial meningitis.

FUNDING

This study was funded by the Meningitis Research Foundation, Pfizer and the NIHR Programme Grants for Applied Research.

Exploring experiences of living with removable dentures-A scoping review of qualitative literature

OBJECTIVE

Examine the literature on the experiences of living with removable dentures (complete or partial) to identify any gaps and provide a map for future research.

BACKGROUND

Increasing proportions of society are living partially dentate with some form of restoration, including removable dentures. Previous studies have reported on the location, materials and usage of these prostheses, along with effects on oral-health-related quality of life (OHRQoL). However, less is known about experiences with removable dentures from a patient-centred perspective.

METHODS

A scoping review of the qualitative literature was undertaken using the framework of Arksey and O'Malley, updated by Levac et al. Literature searches were carried out using Medline and Web of Science. Papers were screened by title and abstract using inclusion and exclusion criteria. Remaining papers were read in full and excluded if they did not meet the required criteria. Nine papers were included in the final review.

FINDINGS

Key themes from these papers were: impact of tooth loss and living without teeth, and its impacts in relation to social position, appearance, confidence and function (chewing and speaking); social norms and tooth loss, including attitudes to tooth retention and treatment costs, and changes in intergenerational norms towards dentures; expectations of treatment, including patients being more involved in decision making, viewing the denture as a "gift" and dentures helping to achieve "an ideal"; living with a removable denture (complete or partial), including patient preparedness for a denture, adaptation and impacts on activities and participation; and the dentist-patient relationship, including issues with information and communication, and differing priorities between patients and dentists.

CONCLUSION

Little qualitative research exists on experiences of living with a removable denture. Existing literature demonstrates the importance of dispersed activities in differing social, spatial and temporal contexts when wearing removable dentures. Focusing on processes of positive adaptation to dentures and OHRQoL, rather than deficits, is also required to fully understand patients' experiences. Additionally, more complex technological advances may not always be in the best interest of every patient.

Epidemiology and mortality in patients hospitalized for burns in Catalonia, Spain

Burn injuries are one of the leading causes of morbidity worldwide. Although the overall incidence of burns and burn-related mortality is declining, these factors have not been analysed in our population for 25 years. The aim of this study has been to determine whether the epidemiological profile of patients hospitalized for burns has changed over the past 25 years. We performed a retrospective cohort study of patients hospitalised between 1 January 2011 and 31 December 2018 with a primary diagnosis of burns. The incidence of burns in our setting was 3.68/105 population. Most patients admitted for burns were men (61%), aged between 35 and 45 years (16.8%), followed by children aged between 0 and 4 years (12.4%). Scalding was the most prevalent mechanism of injury, and the region most frequently affected was the hands. The mean burned total body surface (TBSA) area was 8.3%, and the proportion of severely burned patients was 9.7%. Obesity was the most prevalent comorbidity (39.5%). The median length of stay was 1.8 days. The most frequent in-hospital complications were sepsis (16.6%), acute kidney injury (7.9%), and cardiovascular complications (5.9%). Risk factors for mortality were advanced age, high abbreviated burn severity index score, smoke inhalation, existing cardiovascular disease full-thickness burn, and high percentage of burned TBSA. Overall mortality was 4.3%. Multi-organ failure was the most frequent cause of death, with an incidence of 49.5%. The population has aged over the 25 years since the previous study, and the number of comorbidities has increased. The incidence and severity of burns, and the percentage of burned TBSA have all decreased, with scalding being the most prevalent mechanism of injury. The clinical presentation and evolution of burns differs between children and adults. Risk factors for mortality were advanced age, smoke inhalation, existing cardiovascular disease, full-thickness burn, and high percentage of burned TBSA.

Midbrain and pons MRI shape analysis and its clinical and CSF correlates in degenerative parkinsonisms: a pilot study

OBJECTIVES

To conduct brainstem MRI shape analysis across neurodegenerative parkinsonisms and control subjects (CS), along with its association with clinical and cerebrospinal fluid (CSF) correlates.

METHODOLOGY

We collected demographic and clinical variables, performed planimetric and shape MRI analyses, and determined CSF neurofilament-light chain (NfL) levels in 84 participants: 11 CS, 12 with Parkinson's disease (PD), 26 with multiple system atrophy (MSA), 21 with progressive supranuclear palsy (PSP), and 14 with corticobasal degeneration (CBD).

RESULTS

MSA featured the most extensive and significant brainstem shape narrowing (that is, atrophy), mostly in the pons. CBD presented local atrophy in several small areas in the pons and midbrain compared to PD and CS. PSP presented local atrophy in small areas in the posterior and upper midbrain as well as the rostral pons compared to MSA. Our findings of planimetric MRI measurements and CSF NfL levels replicated those from previous literature. Brainstem shape atrophy correlated with worse motor state in all parkinsonisms and with higher NfL levels in MSA, PSP, and PD.

CONCLUSION

Atypical parkinsonisms present different brainstem shape patterns which correlate with clinical severity and neuronal degeneration. In MSA, shape analysis could be further explored as a potential diagnostic biomarker. By contrast, shape analysis appears to have a rather limited discriminant value in PSP.

KEY POINTS

• Atypical parkinsonisms present different brainstem shape patterns. • Shape patterns correlate with clinical severity and neuronal degeneration. • In MSA, shape analysis could be further explored as a potential diagnostic biomarker.

'Factors influencing future career choices of Queen's University Belfast Medical students.'

INTRODUCTION

Decisions made by medical students on future career choice have demonstrated concordance with subsequent postgraduate career path. This study aimed to understand the factors that impact undergraduate career decision making.

METHODS

An anonymous voluntary survey consisting of binominal, Likert and free text responses was distributed to all medical students registered at Queen's University Belfast (QUB). Data was collected over 6 weeks in April-May 2021. The primary outcome was future career aspirations. The secondary outcomes were the impact of mentorship on career choice, the likelihood of students completing their medical degree and practicing medicine upon graduation. Local ethical approval was obtained.

RESULTS

202 responses were received (response rate 15%). 67% (n = 135) were female. One third of respondents remained undecided about their future career choice. Surgery was both the most popular definite career choice (16.3%) of respondents, butalsothespecialtymarkedmostoftenas'Least preferred Specialty' (33%). Factors positively influencing career choice were academic interest and flexibility in working hours. Negative predictors of career choice were lack of interest in the area, perceived workload, and duration of training schemes. 71% (n=144) of respondents reported that a subspecialty mentor would positively influence their career choice and two-thirds of respondents reported that financial factors would influence their career decision. 11% (n= 22) of respondents were unsure or undecided if they would continue medicine as a career upon graduation.

CONCLUSION

Uncertainty over future career intention remains common with surgery the least popular speciality. Mentorship, integrating flexibility in training and enhancing academic interest should be considered by educational stakeholders as mechanisms to generating undergraduate interest in a subspecialty. Furthermore, the reported rate of students intention to leave their medical degree prior to graduation by this cohort is concerning, warranting further investigation.

Patient Satisfaction with Upper and Lower Complete Dentures: A Service Evaluation Report

PURPOSE

The purpose of this questionnaire-based service evaluation was to assess patient satisfaction with complete dentures provided in a dental teaching hospital.

METHODS

Patients completed the self-administered questionnaire before, immediately after, and 2-months following provision of new complete dentures. The questionnaire consisted of the following sections: Patient characteristics, current denture history and satisfaction with the fit of upper/lower complete dentures, chewing ability, speech, and aesthetics. Descriptive analysis, chi-square test, student t-test, and 2-way-ANOVA were performed on satisfaction levels pre-and post-treatment to assess denture fit, chewing ability, speech, and appearance. Age and gender-wise satisfaction levels along with correlations and associations between patient satisfaction levels and various factors were assessed.

RESULTS

147 participants, including 91 males (61.9%) and 56 females (38.1%) completed the study. A statistically significant improvement in satisfaction scores was seen post-treatment in all domains (p⟨0.05), with most respondents showing great satisfaction. Overall, satisfaction levels were: Upper complete denture fit (82%), appearance (87%), speech (67%), chewing ability and lower complete denture fit (39%). A strong positive correlation was observed between the number of previous dentures used and patient satisfaction with upper denture fit (R=1).

CONCLUSION

Denture replacement positively impacts the satisfaction of patients and improves complete denture acceptance.

Associations among depression, demographic variables, and language impairments in chronic post-stroke aphasia

INTRODUCTION

Depression may influence treatment participation and outcomes of people with post-stroke aphasia, yet its prevalence and associated characteristics in aphasia are poorly understood. Using retrospective data from an overarching experimental study, we examined depressive symptoms and their relationship to demographic and language characteristics in people with chronic aphasia. As a secondary objective, we compared prevalence of depressive symptoms among the overarching study's included and excluded participants.

METHODS

We examined retrospective data from 121 individuals with chronic aphasia including depression scale scores, demographic information (sex, age, time post onset of stroke, education, race/ethnicity, and Veteran status), and scores on assessments of general and modality-specific language impairments.

RESULTS

Approximately 50% of participants reported symptoms indicative of depressive disorders: 23% indicative of major depression and 27% indicative of mild depression. Sex (males) and comparatively younger age emerged as statistically significant variables associated with depressive symptoms; naming ability was minimally associated with depressive symptoms. Time post onset of stroke, education level, race/ethnicity, Veteran status, and aphasia severity were not significantly associated with depressive symptoms. Depression-scale scores were significantly higher for individuals excluded from the overarching study compared to those who were included.

CONCLUSIONS

The rate of depressive disorders in this sample was higher than rates of depression reported in the general stroke literature. Participant sex, age, and naming ability emerged as factors associated with depressive symptoms, though these links appear complex, especially given variable reports from prior research. Importantly, depressive symptoms do not appear to diminish over time for individuals with chronic aphasia. Given these results and the relatively limited documentation of depression in aphasia literature, depression remains a pressing concern for aphasia research and routine clinical care.

21 ASSESSING SARCOPENIA, FRAILTY AND MALNUTRITION IN COMMUNITY-DWELLING DEPENDANT OLDER ADULTS – A HOME-BASED STUDY WITH AN UNDERREPRESENTED GROUP IN RESEARCH

Background

Sarcopenia, frailty, and malnutrition are known determinants of adverse health outcomes. Adults of advanced age, with functional dependency, socioeconomic disadvantage, or a need for home care, are expected to be at high risk of these conditions yet are likely to be underrepresented in research. We aimed to examine the feasibility and preliminary outcomes of conducting home-based assessments in this group.

Methods

Home-based health assessments were conducted among older adults (n= 31), in receipt of state-funded home care. Assessments included probable sarcopenia [hand-grip strength (HGS), chair rise-test and SARC-F case-finding tool] in line with the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) guidelines, the Mini Nutritional Assessment (MNA), and the Clinical Frailty Scale (CFS).

Results

The study group was of mean age 83.2 ± 8.2 years, 74% female, 23% lived in socioeconomically disadvantaged areas, had comorbidities (n=30, 97%) and low physical activity (71%). We found that almost all met the criteria for probable sarcopenia (94%, 29/31), most were frail or vulnerable by CFA (97%, 30/31), and over a quarter were at risk of malnutrition (26%, n=8). In all participants, it was feasible to assess sarcopenia (by HGS and SARC-F, but not chair rise test), malnutrition (MNA), and frailty (CFS). Notably, in-home assessments required additional time, the adaptation of assessment tools, responsibility to address issues arising, including signposting to health services (36%, n=11), and navigating complex psychosocial environments; the latter was commonly observed in areas of socioeconomic disadvantage.

Conclusion

Assessing sarcopenia, frailty, and malnutrition in community-dwelling dependant older adults in-home was feasible, once potential challenges were considered. Moreover, our findings suggest that most participants were at risk of both sarcopenia and frailty, and over a quarter were at risk of malnutrition. This highlights a need for further research and proactive evidence-based multi-modal community interventions to support ageing in place.

OP0221 EFFICACY OF SECUKINUMAB IN ENTHESITIS-RELATED ARTHRITIS: RESULTS FROM A RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED, TREATMENT WITHDRAWAL, PHASE 3 STUDY (JUNIPERA)

Background

Enthesitis-related Arthritis (ERA) is a category of juvenile idiopathic arthritis (JIA) characterised by heterogeneous and insidious manifestations comprising axial and/or peripheral arthritis, and enthesitis.1 Secukinumab (SEC) demonstrated efficacy and safety in both ERA and juvenile psoriatic arthritis (JPsA) in the JUNIPERA trial.2

Objectives

To evaluate the rate of flare risk reduction and efficacy of SEC on axial and peripheral manifestations in patients (pts) with active ERA.

Methods

ERA pts (2 to <18 years of age) with active disease (both ≥3 active joints and ≥1 active enthesitis site) were included. In the open-label (OL) treatment-period (TP)1, s.c. SEC (75/150 mg in pts <50/ ≥50 kg) was administered at baseline (BL), and at Week (Wk) 1–4, 8 and 12. Pts who achieved at least JIA-ACR30 response at Wk 12 were randomised into the double-blinded TP2 to continue SEC or placebo (PBO) every 4 wk until a disease flare, or up to Wk 100. The primary endpoint was time to flare in ERA and JPsA pts. The juvenile spondyloarthritis disease activity Index (JSpADA) is a disease activity assessment tool that contains 8 items to measure axial and peripheral disease activity.3 Evaluation of axial and peripheral manifestations at the end of TP1 and TP2 in pts who experienced these symptoms at BL included modified Schober test (lumbar flexion), inflammatory back pain, FABER (Flexion, ABduction, External Rotation) test, JIA-ACR responses, Juvenile Arthritis Disease Activity Score (JADAS)-27, and resolution of enthesitis and dactylitis for peripheral disease. These outcomes were also used to assess JIA disease course at the end of TP2.

Results

A total of 52/86 (60.5%) pts with ERA were enrolled in the OL period TP1 (mean age, 13.7 years; male, 78.8%). In total, 51/52 (98.1%) pts completed TP1 and 41/44 (93.2%) completed TP2. At BL, mean JADAS-27 was 14.8, mean JSpADA index was 3.9, mean enthesitis and dactylitis counts were 2.7 and 0.4, respectively, mean number of active joints was 6.2 and of mean joints with limited range of motion 4.9. The relative risk reduction of experiencing a disease flare in TP2 was 55% (HR 0.45, 95% CI: 0.16–1.28, p=0.075) in ERA pts (Figure 1). The overall axial and peripheral disease symptoms improved over time and are presented in the Table 1. At the end of TP1, 84.6% (44/52) of pts achieved JIA-ACR 30 and 65.4% (34/52) achieved JIA-ACR 70. Clinically relevant reduction of functional ability as assessed by Childhood Health Assessment Questionnaire (CHAQ) also occurred (see Table 1).

Table 1.

Resolution of axial and peripheral disease symptoms and JIA ACR responses at the end of TP1 and 2

Clinical response, mean (SD) change from BL (unless otherwise stated)TP1-Wk 12End of TP2*SEC (N=52)SEC (N=22)PBO (N=22)JSpADA index−2.4 (1.7)−2.7 (1.7)−2.3 (2.1)JSpADA Schöber, %58.3100.0100.0Inflammatory back pain, %77.8100.050.0FABER test, %52.6100.083.3Clinical sacroiliitis, %53.3100.050.0Enthesitis−2.2 (1.9)−2.5 (2.1)−1.3 (1.8)Dactylitis−0.2 (0.8)−0.2 (1)−0.1 (0.4)JIA ACR30, %84.690.968.2JIA ACR50, %78.881.868.2JIA ACR70, %65.468.254.5JIA ACR90, %32.745.550.0JIA ACR100, %26.936.445.5Inactive disease, %38.550.050.0CHAQ−0.5 (0.5)−0.6 (0.7)−0.4 (0.5)CRP, median (SD) change from BL−1.8 (38.7)−5.8 (38.3)0 (35.9)JADAS-27−9.6 (7.5)−11.0 (8.9)−7.6 (8.9)Resolution of enthesitis#, %72.378.683.3Resolution of dactylitis#, %5066.70

*End of TP2 is based on individual pts’ last visit at TP2. #At BL, in TP1, enthesitis (n= 46); dactylitis (n=5). In TP2, no. of pts who had presence at BL and showed complete resolution at the end of TP2: enthesitis, SEC 14, PBO 18; dactylitis, SEC 3, PBO, 0. CRP, C-reactive protein

Conclusion

In pts with ERA, SEC demonstrated longer time to disease flare vs PBO and exhibited rapid and sustained improvement of axial and peripheral manifestations up to Wk 104.

References

[1]Pagnini I, et al. Front Med 2021;8:6673052.

[2]Brunner H, et al. Arthritis Rheumatol 2021;73 (suppl 10).

[3]Weiss PF, et al. Arthritis Care Res 2014;66:1775-82.

Disclosure of Interests

Nicolino Ruperto Speakers bureau: Eli Lilly, GlaxoSmith and Kline, Pfizer, SOBI and UCB, Paid instructor for: Eli Lilly and Pfizer, Consultant of: Ablynx, Amgen, Astrazeneca-Medimmune, Aurinia, Bayer, Bristol Myers and Squibb, Cambridge Healthcare Research (CHR), Celegene, Domain therapeutic, Eli Lilly, EMD Serono, GlaxoSmith and Kline, Idorsia, Janssen, Novartis, Pfizer, SOBI and UCB, Grant/research support from: Bristol Myers and Squibb, Eli Lilly, F Hoffmann-La Roche, Novartis, Pfizer and SOBI, Elena Chertok: None declared, Joke Dehoorne Speakers bureau: Abbvie, Roche, Consultant of: Abbvie, Roche, Pfizer, Grant/research support from: Abbvie, Roche, Gerd Horneff Speakers bureau: Novartis, Pfizer, Janssen, Grant/research support from: Pfizer, Novartis, Roche, MSD, Tilmann Kallinich Speakers bureau: Roche, Ingrid Louw Speakers bureau: Pfizer, Abbvie, BMS, Consultant of: Pfizer, Abbvie, Janssen, Amgen and Cipla, Sandrine Compeyrot-Lacassagne: None declared, Bernard Lauwerys Employee of: UCB Pharma, Neil Martin: None declared, Katherine Marzan Grant/research support from: Novartis, Sanofi, William Knibbe Speakers bureau: Novartis, Amgen, UCB, Abbvie, Ruvie Martin Shareholder of: Novartis, Employee of: Novartis, Xuan Zhu Shareholder of: Novartis, Employee of: Novartis, sarah whelan Shareholder of: Novartis, Employee of: Novartis, Luminita Pricop Shareholder of: Novartis, Employee of: Novartis, Alberto Martini Speakers bureau: Aurinia, Bristol Myers and Squibb, Eli Lilly, EMD, Janssen, Pfizer, Roche and Serono, Consultant of: Aurinia, Bristol Myers and Squibb, Eli Lilly and EMD, Daniel J Lovell Consultant of: Astra Zeneca, Boehringer Ingelheim, GSK, Hoffman LaRoche, Novartis, UBC, Grant/research support from: Astra Zeneca, Boehringer Ingelheim, GSK, Hoffman LaRoche, Novartis, UBC, Hermine Brunner Consultant of: Novartis, Grant/research support from: Novartis

TNF-inhibitors or bisphosphonates in chronic nonbacterial osteomyelitis? - Results of an international retrospective multicenter study

Chronic nonbacterial osteomyelitis (CNO) can cause significant morbidity, including bone pain and damage. In the absence of clinical trials, treatments include non-steroidal anti-inflammatory drugs, corticosteroids, TNF-inhibitors (TNFi) and/or bisphosphonates. In a retrospective chart review in the United Kingdom and Germany, we investigated response to TNFi and/or pamidronate. Ninety-one patients were included, receiving pamidronate (n = 47), TNFi (n = 22) or both sequentially (n = 22). Patients with fatigue [p = 0.003] and/or arthritis [p = 0.002] were more frequently treated with TNFi than pamidronate. Both therapies were associated with clinical remission at 6 months, and reduction of bone lesions on MRI at 12 months. While not reaching statistical significance, pamidronate resulted in faster resolution of MRI lesions. Fewer flares were observed with TNFi. Failure to respond to pamidronate was associated with female sex [p = 0.027], more lesions on MRI [p = 0.01] and higher CRP levels [p = 0.03]. Randomized clinical trials are needed to confirm observations and generate evidence.

275 Undergraduate Career Aspirations in Northern Ireland - a National Qualitative Study

Introduction

Undergraduate career aspirations are accurately translated to chosen career paths. Understanding what influences these decisions has implications for future workforce planning. The aim of this study was to identify future career intentions in Northern Irish Medical Students.

Method

An anonymous voluntary survey consisting of binominal, Likert and free text responses was distributed to all medical students registered at Queen’s University Belfast (QUB). Data was collected over 6 weeks in April-May 2021. The primary outcome was future career aspiration and secondary outcome was the reported attrition rate from medicine. Local Ethical approval was obtained.

Results

202 responses were received (Response rate 15%). Two thirds (n = 135) were female. One third of respondents remained undecided about their future career choice, with senior students demonstrating greatest certainty in future career choice. Respondents were least likely to choose a career in Surgery (33%). Factors influencing these decisions were a lack of academic interest in the speciality, perceived workload, and the length of the training scheme. 10% of respondents were unsure or unlikely to pursue a career in Medicine after they graduated. Thematic analysis demonstrated, fear of making mistakes, poor work life balance and poor working environments as reasons for leaving medicine.

Conclusions

Uncertainty over future career intention remains common with surgery the least popular speciality. The rate of potential attrition is concerning which warrants further investigation.

272 Factors Influencing Medical Student Future Career Choice – Why Not Surgery?

Introduction

Decisions made by medical students on future career choice have demonstrated consistency with resulting postgraduate career path. The aim of this qualitative study was to identify factors influencing career choice amongst medical students in Northern Ireland.

Method

An anonymous voluntary non-monetised survey consisting of binominal, Likert and free text responses was distributed to all medical students registered at Queen’s University Belfast (QUB). Data was collected over 6 weeks in April-May 2021. Primary outcomes were factors influencing future career choice and the secondary outcomes were the impact of finance and mentorship on ultimate career choice. Local ethical approval was obtained.

Results

202 responses were received (Response rate 15%). 67% (n = 135) were female. One third of respondents remained undecided about their future career choice. Respondents were least likely to choose a career in Surgery (33%). Factors positively influencing career choice were academic interest and flexibility in working hours. Negative predictors of career choice were lack of interest in the area, perceived workload, and duration of training schemes. 71% (n = 144) of respondents reported that a subspecialty mentor would positively influence their career choice and two-thirds of respondents reported that financial factors would not influence their career decision.

Conclusions

Surgery was the least the popular specialty. Mentorship, integrating flexibility in training and enhancing academic interest may create greater traction for prospective trainees to surgery.

Regulation of membrane phospholipids during the adult life of worker honey bee

Two female castes that are genetically identical are found in honey bees: workers and queens. Adult female honey bees differ in their morphology and behaviors, but the most intriguing difference between the castes is the difference in their longevity. Queens live for years while workers live generally for weeks. The mechanisms that mediate this extraordinary difference in lifespan remain mostly unknown. Both castes share similar developmental stages and are fed liquid food (i.e. a jelly) during development. However, after emergence, workers begin to feed on pollen while queens are fed the same larval food for their entire life. Pollen has a high content of polyunsaturated fatty acids (PUFA) while royal jelly has negligible amounts. The difference in food during adult life leads to drastic changes in membrane phospholipids of female honey bees, and those changes have been proposed as mechanisms that could explain the difference in lifespan. To provide further details on those mechanisms, we characterized the membrane phospholipids of adult workers at seven different ages covering all life-history stages. Our results suggest that the majority of changes in worker membranes occur in the first four days of adult life. Shortly after emergence, workers increase their level of total phospholipids by producing phospholipids that contained saturated (SFA) and monounsaturated fatty acids (MUFA). From the second day, workers start replacing fatty acid chains from those pre-synthesized molecules with PUFA acquired from pollen. After four days, worker membranes are set and appear to be maintained for the rest of adult life, suggesting that damaged PUFA are replaced effectively. Plasmalogen phospholipids increase continuously throughout worker adult life, suggesting that plasmalogen might help to reduce lipid peroxidation in worker membranes. We postulate that the diet-induced increase in PUFA in worker membranes makes them far more prone to lipid-based oxidative damage compared to queens.

Field-induced vortex-like textures as a probe of the critical line in reentrant spin glasses

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