Low temperature Raman spectroscopic study of anharmonic and spin-phonon coupled quasi-two dimensional rare earth based francisites

Mineral francisites Cu3Bi(SeO3)2O2Cl are unique compounds with interesting quasi two-dimensional structure along with fascinating magnetic properties. The magnetic properties can be fine-tuned when non-magnetic Bi is replaced by a suitable rare earth (RE) metal. It is because of the inclusion of additional magnetic sub-centre RE apart from Cu. Temperature dependent Raman spectroscopy measurements in RE based francisites [Cu3RE(SeO3)2O2Cl, shortly RECufr] were performed in the range of 11 K-295 K. Among the three studied RECufr (LaCufr, NdCufr, and DyCufr) compounds, the properties of phonon vibration vary from moderate (in DyCufr) to weak (in LaCufr) spin phonon coupled and the absence of spin phonon coupling (SPC) (i.e. strictly anharmonic in nature) was observed in NdCufr and the reason for this observation has been provided. More specifically, two Raman-active phonons soften below the antiferromagnetic ordering temperature ofTN≈ 39 K in DyCufr compound, indicating the existence of moderate SPC. This trend of phonon vibration is correlated with magnetic properties, particularly field induced metamagnetic transition (MMT). Strong MMT enabled DyCufr develops SPC, while weak MMT enabled NdCufr is unable to develop SPC.

Motivation and accessing care among drug treatment court involved women: A sequential, mixed-methods approach

Drug treatment courts (DTC) address substance use disorders (SUD) but not cooccurrencing HIV or hepatitis C virus (HCV). This pilot explored feasibility and preliminary outcomes of the Women's Initiative Supporting Health (WISH) intervention and health-related motivation, both based in self-determination theory (SDT) regarding HIV/HCV and SUD treatment. WISH feasibility study: 79 DTC women completed a one-time survey regarding motivation and willingness to engage in future interventions. WISH intervention: 22 women from DTC with SUD and HIV or HCV received a 6-session, peer motivational enhancement health behavior-oriented interventions. Recruitment strategies were feasible. SDT-based measures demonstrated internal consistency in this under-studied population, with perceived competence/autonomy associationed with motivation to reduce HIV/HCV/SUD risk. Women DTC participants indicated acceptance and showed internally consistent results in SDT-based motivation measures These WISH feasibility and intervention pilot studies lay a foundation for future studies addressing motivation to access healthcare among women DTC participants.

Highly correlated structural, local structural, Raman spectroscopic and magnetic properties of Mn-substituted Cu2V2O7

Low-dimensional quantum spin ½ system Cu2V2O7has been investigated in the framework of Mn-substitution at the Cu site, which is really un-investigated. The studied compounds Cu2 -xMnxV2O7(x= 0, 0.05, 0.1 and 0.15) have been synthesized and characterized structurally, spectroscopically, local structurally and magnetically via x-ray diffraction, Raman, x-ray absorption and temperature, field dependent magnetization measurements respectively. Although Cu2V2O7can be found inα, βandγ-phase, however all of the studied compounds are found in single orthorhombicα-phase which has crucial magneto-electric application potential. Temperature dependent Raman spectra indicated anharmonic phonon-phonon scattering but there is no spin-phonon coupling for VO4vibrational modes. The local structure probed via x-ray absorption near edge structure and extended x-ray absorption fine structure spectroscopy at 15 K, 300 K indicates Cu2+, V5+and mixed valent Mn2+and Mn3+ionic states and justified local structure for the probed ions. Magnetic measurements indicate long-range antiferromagnetic ordering with doping independent Neel temperature (32.5 K). Further observations are strong magnetic hysteresis at 5 K (due to canted spin structure), zero field exchange-bias and their noteworthy enhancement upon Mn-substitution. Interesting correlation between structural parameters and magnetic exchanges has been developed.

Phthalate exposure in the neonatal intensive care unit is associated with development of bronchopulmonary dysplasia

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is a serious yet common morbidity of preterm birth. Although prior work suggests a possible role for phthalate exposure in the development of BPD, no study has rigorously evaluated this. Our objective was to determine whether hospital-based phthalate exposure is associated with the development of BPD and to identify developmental windows sensitive to exposure.

STUDY DESIGN

This is a prospective multicenter cohort study of 360 preterm infants born at 23-33 weeks gestation participating in the Developmental Impact of NICU Exposures (DINE) cohort. 939 urine specimens collected during the NICU stay were analyzed for biomarkers of phthalate exposure by liquid chromatography with tandem mass spectrometry. The modified Shennan definition was used to diagnose bronchopulmonary dysplasia. Reverse distributed-lag modeling identified developmental windows sensitive to specific phthalate exposure, controlling for relevant covariates including sex and respiratory support.

RESULTS

Thirty-five percent of participants were diagnosed with BPD. Exposure to specific phthalate mixtures at susceptible points in preterm infant development are associated with later diagnosis of BPD in models adjusted for use of respiratory support. The weighted influence of specific phthalate metabolites in the mixtures varied by sex. Metabolites of di(2-ethylhexyl) phthalate, a phthalate previously linked to neonatal respiratory support equipment, drove this association, particularly among female infants, at 26- to 30-weeks post-menstrual age.

CONCLUSIONS

This is the largest and only multi-site study of NICU-based phthalate exposure and clinical impact yet reported. In well-constructed models accounting for infant sex and respiratory support, we found a significant positive association between ultimate diagnosis of BPD and prior exposure to phthalate mixtures with DEHP predominance at 26- to 30-weeks PMA or 34-36-weeks PMA. This information is critically important as it identifies a previously unrecognized and modifiable contributing factor to BPD.

Stroke death in patients receiving radiation for head and neck cancer in the modern era

Objectives

Head and neck cancer is a common malignancy frequently treated with chemotherapy and radiotherapy. Studies have shown an increased risk of stroke with the receipt of radiotherapy, but data on stroke-related mortality are limited, particularly in the modern era. Evaluating stroke mortality related to radiotherapy is vital given the curative nature of head and neck cancer treatment and the need to understand the risk of severe stroke in this population.

Methods

We analyzed the risk of stroke death among 122,362 patients (83,651 patients who received radiation and 38,711 patients who did not) with squamous cell carcinoma of the head and neck (HNSCC) diagnosed between 1973 and 2015 in the SEER database. Patients in radiation vs. no radiation groups were matched using propensity scores. Our primary hypothesis was that radiotherapy would increase the hazard of death from stroke. We also examined other factors impacting the hazard of stroke death, including whether radiotherapy was performed during the modern era when IMRT and modern stroke care were available as well as increased HPV-mediated cancers of the head and neck. We hypothesized that the hazard of stroke death would be less in the modern era.

Results

There was an increased hazard of stroke-related death in the group receiving radiation therapy (HR 1.203, p = 0.006); however, this was a very small absolute increase, and the cumulative incidence function of stroke death was significantly reduced in the modern era (p < 0.001), cohorts with chemotherapy (p=0.003), males (p=0.002), younger cohorts (p<0.001) and subsites other than nasopharynx (p=0.025).

Conclusions

While radiotherapy for head and neck cancer increases the hazard of stroke death, this is reduced in the modern era and remains a very small absolute risk.

P-116 UNUSUAL VISCERAL CONTENT IN PARASTOMAL HERNIAS - A REVIEW OF LITERATURE

Parastomal hernias remain the most common complication of an ileostomy or colostomy - It is estimated that upto 50 percent of patients with a stoma will develop one. They may be classified as Interstitial, Subcutaneous, Intrastomal or Peristomal. The most common contents of Parastomal Hernias are bowel and omentum.However, other visceras have been reported as a content of a parastomal hernia. This presentation is aimed at a literature review of such surprise surgical situations that are challenging to the surgeons.

Presence of gallbladder in a parastomal hernia has been reported by multiple authors - there is reported incidence of incarceration or acute inflammation of the gallbladder. Cholecystectomy t the time of parastomal hernia repair has been reported though some patients have been treated non-operatively as well.

Similarly, there have been multiple reports of stomach beong the contents of parastomal hernias - there have been patients presenting with gastric outlet obstruction who have been found to have the stomach being a content of their parastomal herniation.

This presentation reviews the available literature and presents the challenges and oprions that a surgeon may face when treating similar patients.

P-115 HYBRID REPAIR OF RECURRENT COMPLEX GROIN HERNIA - CHALLENGES AND LESSONS LEARNT

A 45 year old lady presented with a recurrent swelling over the right groin that had gradually turned tense and tender over the last 48 hours. Having undergone an urgent right femoral hernia repair in 2002, she underwent an inguinal hernioplasty in 2004 and amesh repair of a recurrent inguinal hernia in 2008. She developed a third recurrence that slowly increased in size and needed an urgent repair. At assessment, she was found to have a large complete recurrent irreducible right inguinal hernia containing loops of bowel.

At laparoscopy, multiple loops of bowel and omentum were reduced from a large multiloculated hernial sac. In view of the large sac which had incorporated the previously placed meshes in the wall, a decision was made to abandon laparoscopic approach. The myopectineal orifice was approached through a groin incision and the hernial sac with it's locules, including a prevascular component, was defined. The posterior sheath was defined and the rigt rectus muscle, displaced by the hernia, was repositioned. The dissection was carried upto the Space of Bogros to ensure that no component of the hernia was missed out. After completing a formal herniotomy, a sandwich prosthesis, created by stitching a biomesh and a polypropylene mesh, was utilised for hernia repair.

The patient had an uneventful recovery.

The presentation is aimed at discussing the challenges of repairing a complex recurrent hernia, the possible pitfalls and lessons learnt.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Aberrant newborn T cell and microbiota developmental trajectories predict respiratory compromise during infancy

Neonatal immune-microbiota co-development is poorly understood, yet age-appropriate recognition of - and response to - pathogens and commensal microbiota is critical to health. In this longitudinal study of 148 preterm and 119 full-term infants from birth through one year of age, we found that postmenstrual age or weeks from conception is a central factor influencing T cell and mucosal microbiota development. Numerous features of the T cell and microbiota functional development remain unexplained; however, by either age metric and are instead shaped by discrete perinatal and postnatal events. Most strikingly, we establish that prenatal antibiotics or infection disrupt the normal T cell population developmental trajectory, influencing subsequent respiratory microbial colonization and predicting respiratory morbidity. In this way, early exposures predict the postnatal immune-microbiota axis trajectory, placing infants at later risk for respiratory morbidity in early childhood.

Increased risk of high-grade prostate cancer among testicular cancer survivors

Introduction

Testicular cancer survivors (TCS) have an increased risk of additional cancers, including prostate cancer. Our understanding of the natural history of prostate cancer in testicular cancer survivors is very limited due to its rare incidence.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) Registry from 1978 to 2011, we identified 282 TCS with subsequent prostate cancer and examined the tumor grade and clinical outcomes in contrast to men with primary prostate cancer in the general population.

Results

TCS with a subsequent prostate cancer diagnosis were more likely to be diagnosed at a younger age than men with primary prostate cancer (65.2% vs. 37.6% for age ≤65, 34.8% vs. 62.4% for age >65, p<0.001) and were more likely to have grade III/IV tumors (46.2% vs. 37.0%, p<0.002). Longer latency between testicular and prostate cancer diagnoses was associated with a higher risk of grade III/IV (p<0.001) cancer. Despite the increased risk for high-grade tumors, 10-year prostate cancer-specific survival and overall survival were not significantly different between TCS and men with primary prostate cancer. Based on the available information in SEER, we found that prior history of radiotherapy for testicular cancer had no impact on tumor grade or survival outcomes.

Conclusions

Prostate cancer in TCS was more likely to be diagnosed at a younger age and with higher grades. Risks of grade III/IV disease increased with longer latency between testicular and prostate cancer diagnoses. Radiotherapy for testicular cancer did not appear to have a significant impact on the outcome of subsequent prostate cancer.

Prevalence and molecular characterization of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from dogs suffering from diarrhea in and around Kolkata

BACKGROUND

Dogs are the favorite companion animals among humans. The close interaction between dogs and people increases the risk of antibiotic resistance spreading. Surveillance for antimicrobial resistance and the identification of ESBL-producing Escherichia coli as an indicator bacterium is an important tool for managing antimicrobial drug therapy.

AIMS

The present study targeted to identify and characterize ESBL-producing E. coli among dogs suffering from diarrhea in and around Kolkata.

METHODS

Isolation and identification of E. coli from dogs suffering from diarrhea (n=70) along with screening for the production of both ESBL and AmpC. The isolates were further characterized through antimicrobial resistance profiling, resistance genes (bla _CTX-M, bla _TEM, and bla _SHV) screening, and phylogenetic group study.

RESULTS

Among the 70 isolates, 21 (30%) were confirmed ESBL producers. An antibiogram typing of ESBL-producing E. coli revealed that the majority of them were resistant to norfloxacin (85.7%) followed by tetracycline (61.90%), doxycycline (57.14%), piperacillin/tazobactam (52.38%), cotrimoxazole (47.62%), gentamicin (42.62%), amikacin (23.81%), and chloramphenicol (19.05%). Major resistance genes included bla _CTX-M (100%), bla _TEM (28.57%), and bla _SHV (9.50%). The predominant phylogenetic groups were phylogroup A (76%) followed by phylogroup D (24%).

CONCLUSION

The current investigation reported a high prevalence of both ESBL and AmpC β-lactamase (AmpC) producing E. coli, co-resistance to a distinct group of antibiotics, and co-existence of different ESBL genes in dogs. Our findings highlight the importance of diagnostic antimicrobial susceptibility testing for proper antimicrobial therapy and to prevent antimicrobial resistance from spreading to humans from dogs in Kolkata and the surrounding area.

Absence of clinical benefit of FDG PET-CT in staging T1 part-solid lung adenocarcinoma

AIM

To assess the rates of nodal and metastatic disease and change in management when staging part-solid T1 lung adenocarcinomas using integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) in a UK population.

MATERIALS AND METHODS

This was a retrospective review of PET-CT examinations performed to stage radiologically suspected T1 part-solid lung adenocarcinoma (n=58) from two different centres. Rates of detection of nodal and metastatic disease, change in management, and final patient outcome were recorded.

RESULTS

PET-CT changed the stage in one patient from N0 to N1. It did not change final management in any patient.

CONCLUSIONS

In this UK population, PET-CT had minimal additional diagnostic benefit in staging patients with T1 part-solid lung adenocarcinoma. Especially given its cost, the inclusion of PET-CT for this indication in guidelines should be reviewed.

Effect of Co and Mg doping at Cu site on structural, magnetic and dielectric properties of α-Cu2V2O7

We have studied the effect of doping of both magnetic (Co) and nonmagnetic (Mg) ions at the Cu site on phase transition in polycrystalline α-Cu₂V₂O₇through structural, magnetic, and electrical measurements. X-ray diffraction reveals that Mg doping triggers an onset ofα- toβ-phase structural transition in Cu_2-xMg_xV₂O₇above a critical Mg concentrationx_c= 0.15, and both the phases coexist up tox= 0.25. Cu₂V₂O₇possesses a non-centrosymmetric crystal structure and antiferromagnetic ordering along with a non-collinear spin structure in theαphase, originated from the microscopic Dzyaloshinskii-Moriya interaction between the neighboring Cu spins. Accordingly, a weak ferromagnetic (FM) behavior has been observed up tox= 0.25. However, beyond this concentration, Cu_2-xMg_xV₂O₇exhibits complex magnetic properties. A clear dielectric anomaly is observed in α-Cu_2-xMg_xV₂O₇around the magnetic transition temperature, which loses its prominence with the increase in Mg doping. The analysis of experimental data shows that the magnetoelectric coupling is nonlinear, which is in agreement with the Landau theory of continuous phase transitions. Co doping, on the other hand, initiates a sharpαtoβphase transition around the same critical concentrationx_c= 0.15 in Cu_2-xCo_xV₂O₇but the FM behavior is very weak and can be detected only up tox= 0.10. We have drawn the magnetic phase diagram which indicates that the rate of suppression in transition temperature is the same for both types of doping, magnetic (Co) and nonmagnetic (Zn/Mg).

22 Motivations, Barriers, And Social Media: A Qualitative Study of Uptake of Women into Neurosurgery

Objective

To explore how social media could be utilised to influence an individual’s motivation to pursue a neurosurgical career, an emerging topic area. The focus of this study was on women interested in neurosurgery.

Background

Women are significantly under-represented in neurosurgery. 18% of all neurosurgeons – including 8% of consultants – are women. Most previous studies have used quantitative methods that are not best suited to gaining an in-depth understanding of the barriers that women face in pursuing a career in neurosurgery, or what would enable more women to go into the speciality.

Method

In this qualitative study, individual semi-structured interviews were conducted until data saturation was achieved. Participants were women pre-neurosurgical trainees. The interview data was examined through a thematic analysis involving open and axial coding.

Results

Thirty women participated in the study. Four overarching themes were identified: (1) mentorship, (2) testimony from other women doing neurosurgery, (3) social media as a means of increasing interest in neurosurgery as a career choice, and (4) real-life exposure to the speciality.

Conclusions

There is scope to further improve uptake of women into neurosurgical training in the UK. Motivations and barriers to women pursuing neurosurgery should be addressed openly through early experience, role models and mentorship. Social media can help facilitate these opportunities, disseminate information and inspiration, and has the potential to undo societal biases.

476 The Role of Medical Students in an International, Collaborative, Multi-Centre Global Surgery Study

Introduction

The gaps in formal education caused by the pandemic have provided medical students with opportunities to redefine their role in settings across clinical medicine, education and research. This task shifting could provide avenues for students to engage with global surgery, where the cultivation of research skills, networking, and global collaboration amongst students is imperative for sustainable progress.

COVIDPaedsCancer is an international collaborative cohort study assessing the impact of the pandemic on paediatric cancer services. We aimed to trial a student and junior doctor-lead team to perform the day-to-day running of this research.

Method

An operations team of 47 students and junior doctors across 11 countries was assembled. Sub-teams were created for social media, network management, email communications, REDCap, research support and graphics. Together, they ran the study under guidance from the steering committee.

Results

To date, the operations team has coordinated study collaborators in collecting data for 1252 patients from 78 centres across 39 countries. Cooperation between sub-teams enabled the recruitment of collaborators from 558 hospitals in total. They also identified 2 errors in the protocol and resolved them with steering committee input, and continuously managed hospital leadership issues and general queries throughout the course of the study. The team was able to adapt in response to the evolving needs of collaborators and the steering committee.

Conclusions

Medical students were able to aid the delivery of an international, multicentre, collaborative, global surgery research study while benefiting from learning opportunities, networking opportunities, and developing interest and understanding of global surgery.

244 Traumatic Brain Injury Related Paediatric Mortality and Morbidity in Low- And Middle-Income Countries: A Systematic Review and Meta-Analysis

Aim

Three million cases of paediatric traumatic brain injury (pTBI) occur annually, the majority of which occur in low-and-middle-income countries (LMICs). However, there is a paucity of data on the outcomes of pTBI available. We aimed to systematically review and synthesise the reported morbidity and mortality from pTBI in the published literature about LMICs.

Method

A systematic review and meta-analysis were conducted. MEDLINE, EMBASE, Global Health, and Global Index Medicus were searched for relevant articles from January 2000 to May 2020. Observational or experimental studies on pTBI (individuals between the ages of 0 to 16 years) in LMICs were included. Morbidity data were descriptively analysed, and a random-effects model was used to pool mortality rates. PROSPERO ID: CRD42020171276.

Results

We included 145 studies from 38 countries representing 174073 patients with pTBI. Males were twice (95% CI: 1.6 – 2.4) as likely to have a pTBI than females. Where available, mild TBI represented ≥ 60% of all pTBI cases in most reports (n = 24/43, 56%). The commonest cited cause of pTBI was road traffic accidents (n = 16643/43083, 39%), followed by falls (n = 10927/43083, 25%). 4385 patients (n = 4385/18092, 24%) had a reduction from normal function on discharge. On average, there were 6.7 deaths per 100 cases of pTBI.

Conclusions

Only 38 LMICs have published data on the volume and burden of pTBI in their country. Limited data available suggests that young male children are at a high-risk of pTBIs in LMICs, particularly from road traffic accidents.

Risk of adverse pathological features for intermediate risk prostate cancer: Clinical implications for definitive radiation therapy

BACKGROUND

Intermediate risk prostate cancer represents a largely heterogeneous group with diverse disease extent. We sought to establish rates of adverse pathological features important for radiation planning by analyzing surgical specimens from men with intermediate risk prostate cancer who underwent immediate radical prostatectomy, and to define clinical pathologic features that may predict adverse outcomes.

MATERIALS AND METHODS

A total of 1552 men diagnosed with intermediate risk prostate cancer who underwent immediate radical prostatectomy between 1/1/2005 and 12/31/2015 were reviewed. Inclusion criteria included available preoperative PSA level, pathology reports of transrectal ultrasound-guided prostate biopsy, and radical prostatectomy. Incidences of various pathological adverse features were evaluated. Patient characteristics and clinical disease features were analyzed for their predictive values.

RESULTS

Fifty percent of men with high risk features (defined as PSA >10 but <20 or biopsy primary Gleason pattern of 4) had pathological upstage to T3 or higher disease. The incidence of upgrade to Gleason score of 8 or higher and the incidence of lymph node positive disease was low. Biopsy primary Gleason pattern of 4, and PSA greater than 10 but less than 20, affected adverse pathology in addition to age and percent positive biopsy cores. Older age and increased percentage of positive cores were significant risk factors of adverse pathology.

CONCLUSION

Our findings underscore the importance of comprehensive staging beyond PSA level, prostate biopsy, and CT/bone scan for men with intermediate risk prostate cancer proceeding with radiation in the era of highly conformal treatment.

AB0223 MODIFIED DOSE RITUXIMAB BIOSIMILAR IN RHEUMATOID ARTHRITIS COMPARING B-CELL DEPLETION EFFECT AND DISEASE ACTIVITY SCORES

Background:

In emerging economies self-funding patients opt for less costly options, influencing both compliance and maintenance of treatment for chronic illness. Studies comparing originator rituximab 1000mgx2 and 500mgx2 doses in Rheumatoid arthritis (RA) have yielded interesting results1. Evidence of B cell depletion, measured by CD19 count, maybe a marker for disease improvement2. However effect of different dose of biosimilar Rituximab (bRTX) on B cell depletion and disease activity needs exploration.

Objectives:

To determine correlation of CD19 count defining B cell depletion and disease activity with different dosages of bRTX treatment.

Methods:

Between April 2019 and March 2020, all RA patients with DMARD failure were screened for eligibility of biologics as routine clinical practice. Depending on individual choice, after full consent, patients received either 1000mgx2 or 500mgx2 bRTX. All patients had CD19 count before and 12 months after the first dose. Effectiveness of bRTX 1000 mg×2 and 500 mg×2 was assessed by DAS28 and EULAR response. Comparative adjusted analysis was performed by analysis of variance (ANOVA).

Results:

Out of 468 eligible patient, 84 opted for biologic. Of which 27 patients consented for bRTX (17 female, mean age 39.5 years).13 patients opted for 1000mg×2 and 14 for 500mg×2 dose. 74% (20/27) patients were on concomitant methotrexate and 26% on hydroxychloroquine (7/27). Both doses led to significant reduction in ESR, CRP, and DAS28-ESR at 12 months (p<0.001) (Table 1).

Table 1.

RA outcome-measurement scores at 12 months post biosimilar Rituximab therapy.

VariableBaseline12 monthsRTX 1000mg x 2(n=13)RTX 500mg x 2(n=14)RTX 1000mg x 2(n=13)RTX 500mg x 2(n=14)ESR*53.9±23.957.1±24.723.9±2.924.1±4.7CRP*6.1±3.96.9±2.92.1±0.92.3±0.9DAS28-ESR*6.1±0.36.1±0.24.0±0.44.1±0.2CD 19+ Count*# (105/L)1191.6±308.41155±289.6128.8±90.4139±90.6

* p<0.0001 as compared to 12 mos vs baseline; # p<0.0001 as compared amongst group

At the end of 12 months, compared to 1000mg, CD19 count was higher in 500mg group (p=0.25). Percentage of patients achieving EULAR moderate or no response was higher in 500mg group (37%vs29%, p=0.205), both complete and incomplete B cell depletion, but patients achieving good response was same in both groups (14.8%vs18.5%, p = 0.25). (Figure 1).

Figure 1.

EULAR Response at 12 months

Conclusion:

Low dose bRTX is effective in DMARD refractory RA patients with similar improvements as regular dose, although CD19 depletion was less in low dose group. A larger study to establish radiographic regression with CD19 depletion and disease activity score can help in further strengthening the use of lower dose bRTX in RA leading to significant economic advantage.

References:

[1]Chatzidionysiou K, Lie E, Nasonov E, Lukina G,et al. Rheumatic Diseases Portuguese Register. Effectiveness of two different doses of rituximab for the treatment of rheumatoid arthritis in an international cohort: data from the CERERRA collaboration. Arthritis Res Ther. 2016 Feb 16;18:50.

[2]Vital EM, Rawstron AC, Dass S, Henshaw K, Madden J, Emery P, McGonagle D. Reduced-dose rituximab in rheumatoid arthritis: efficacy depends on degree of B cell depletion. Arthritis Rheum. 2011 Mar;63(3):603-8.

Disclosure of Interests:

None declared

Temporal Dysbiosis of Infant Nasal Microbiota Relative to Respiratory Syncytial Virus Infection

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of infant respiratory disease. Infant airway microbiota has been associated with respiratory disease risk and severity. The extent to which interactions between RSV and microbiota occur in the airway, and their impact on respiratory disease susceptibility and severity, are unknown.

METHODS

We carried out 16S rRNA microbiota profiling of infants in the first year of life from (1) a cross-sectional cohort of 89 RSV-infected infants sampled during illness and 102 matched healthy controls, and (2) a matched longitudinal cohort of 12 infants who developed RSV infection and 12 who did not, sampled before, during, and after infection.

RESULTS

We identified 12 taxa significantly associated with RSV infection. All 12 taxa were differentially abundant during infection, with 8 associated with disease severity. Nasal microbiota composition was more discriminative of healthy vs infected than of disease severity.

CONCLUSIONS

Our findings elucidate the chronology of nasal microbiota dysbiosis and suggest an altered developmental trajectory associated with RSV infection. Microbial temporal dynamics reveal indicators of disease risk, correlates of illness and severity, and impact of RSV infection on microbiota composition.

721 Imaging for Suspected Bowel Obstruction in Pennine Acute Trust (PAT): A Comparison with the National Audit of Small Bowel Obstruction’s (NASBO) recommendations

Background

NASBO recommends Computed Topography (CT) over plain abdominal X-ray (AXR) for the investigation of bowel obstruction (BO). AXR is routinely used within PAT for investigation of BO which may be exposing patients to unnecessary radiation and adding unnecessary cost to the service.

Method

A retrospective audit collected data on patients with CT confirmed BO between July 2019 and February 2020. This looked at the percentage of patients who had both CT and AXR to investigate BO. The cost of these AXRs and the percentage of these AXRs that were normal were also calculated.

Results

A search identified 141 patients with CT proven BO. 81/141(57.4%) patients had both AXR and CT as a part of their initial investigations. Of those patients 26/81(32.1%) had no AXR features suggestive of BO. Only 12/81(14.8%) of those patients had serial AXRs following initial imaging. The cost for one AXR is £34.15 which means £2766.15 was spent on potentially unnecessary AXRs within this period.

Conclusions

PAT is performing potentially unnecessary AXRs which is exposing patients to unnecessary radiation and costing the trust. Plain AXRs do not rule out BO. We have recommended an investigation flowchart to PAT A&E departments to reduce unnecessary AXRs being performed.

77 The Development of Core Outcome Sets and Common Data Elements in Clinical Neurosciences: A Scoping Review

Introduction

The use of core outcome sets (COS) and common data elements (CDEs) minimises research wastage by increasing the cross-comparison and meta-analysis of study findings. Our study sought to identify the clinical neuroscience subspecialties that have developed COS and CDEs, the countries of origin of authors, and the process through which COS and CDEs were developed.

Method

A search between 2000-2020 of the top 40 Impact Factor neurosurgical and neurological journals was conducted. A scoping review was performed in accordance with the PRISMA-ScR Checklist.

Results

Our search returned 169 papers, of which 35 were eligible for inclusion. The USA published the majority of papers (20/35). The papers mostly related to neurosurgery (30/35), with the most common neurosurgical sub-specialty being traumatic brain injury (14/35). There is an increasing publication trend over time, with 12 papers published in 2019. Five papers were systematic reviews conducting with the intention of COS/CDE development. 27 papers reported CDE development and 2 papers reported COS development. The COS development papers utilised international consensus meetings and adhered to international development statements.

Conclusions

COS and CDEs are increasingly being developed within clinical neurosciences. There is a need for greater international collaboration with regards to COS and CDEs development.

13 Medical Students’ Mood Adversely Affected By COVID-19 Pandemic: An Interim Analysis from the SPICE-19 Prospective Cohort Study Of 2075 Medical Students and Interim Foundation Doctors

Introduction

In order to appropriately support medical students and foundation year doctors, it is imperative that we understand the impact the COVID-19 pandemic has had upon them. This study assessed the effects of the COVID-19 pandemic on medical students and interim foundation year doctors across the United Kingdom (UK), and the support that they received and sought.

Method

A prospective, observational, multicentre study was conducted. All medical students and interim foundation year doctors were eligible to participate.

Results

A total of 2075 individuals participated. There was a decrease in participants’ mood when comparing their mood before the pandemic to during the pandemic (p < 0.0001). Social distancing negatively impacted the mood of the greatest number of participants. All areas of life included in the study were found to have been significantly more negatively impacted than positively impacted (p < 0.0001). 931 participants wanted more support from their university.

Conclusions

When medical students return to their universities, there is likely to be a need for enhanced wellbeing support, adaptations in the short-term and long-term strategies for medical education, and provision of financial guidance. If no action is taken, there may be a knock-on effect on workforce planning and the health of our future workforce.

Metal contaminations in sediment and associated ecological risk assessment of river Mahanadi, India

Mahanadi is one of the major rivers of peninsular India. Like other Indian rivers, it is contaminated with sewages, industrial discharges, and agricultural runoff. Thus, necessity was felt to monitor its pollution status. Present work was part of that program and aimed to assess the sediment contamination due to the trace metals Cd, Cr, Cu, Mn, Pb, and Zn during 2012-2015. Sediment pollution status and ecological risks were evaluated calculating contamination factor (CF), geo-accumulation (I_geo), pollution load index (PLI), potential ecological risk (EⁱR), etc. The recorded metal concentrations were Cd BDL of flame mode of AAS; Cr BDL - 73.9; Cu BDL - 44.4; Mn 37.2 - 1887.0; Pb BDL - 29.5; and Zn BDL - 92.5 mg kg^-1. As per US EPA guidelines, Cr concentrations at many locations were in the moderately polluted range. I_geo, CF, mC_d, PLI, and EⁱR indicated low pollution levels and low ecological risks due to the trace metals assessed. The sediment quality guidelines (SQGs) indicated that Cr and Cu concentrations exceeded (16% sample) the threshold effect concentrations and may occasionally exhibit adverse biological effects. The association of sediment organic matter, conductivity and content of Cu, and their grouping in component 1 of PCA revealed that the anthropogenic input was dominant and so also the component 2 where Cr exhibited moderately good correlation with organic matter. Cluster analysis of the sampling sites based on pollution status yielded 3 groups: relatively uncontaminated (S3, S4), low to moderately contaminated (S2), and moderately contaminated (S1, S5, S6) stretches.

The Biopsychosocial Model and Perinatal Health Care: Determinants of Perinatal Care in a Community Sample

Insufficient care in the perinatal period is associated with poorer maternal health, poorer perinatal outcomes, infant mortality, and health inequalities. Identifying the sources of and reducing the rates of insufficient care is therefore a major clinical and public health objective. We propose a specific application of the biopsychosocial model that conceptualizes prenatal and postpartum care quality as health markers that are influenced by psychological factors and family and social context. Clinic attendance data were abstracted from the electronic medical records of N = 291 participants enrolled in a longitudinal pregnancy cohort study of healthy women who have been followed since the first trimester; the Kotelchuck Index (KI) was calculated as an index of perinatal care utilization. Detailed prenatal psychological, social, and sociodemographic data were collected from self-report questionnaire and interview. Bivariate analyses indicated socio-demographic (e.g., race), psychological (e.g., response to perceived racism, affective symptoms, trauma experience), and social and family context (e.g., social support, family size) significantly influenced pre- and post-natal care utilization. Multivariate logistic regression analyses, adjusting for medical complications, identified social and family context as robust predictors of perinatal care utilization. The findings underscore the need for biopsychosocial models of health care and highlight several potential strategies for improving health care utilization.

Multi-drug resistant, biofilm-producing high-risk clonal lineage of Klebsiella in companion and household animals

Antimicrobial resistance is a global emergency which needs one health approach to address. The present study was conducted to detect the prevalence of beta-lactamase and biofilm-producing Klebsiella strains in rectal swabs (n = 624) collected from healthy dogs, cats, sheep and goats reared as companion or household animals in India. The dogs and cats were frequently exposed to third- or fourth-generation cephalosporins for therapy. The sheep and goats were occasionally exposed to antibiotics and had environmental exposure. Phenotypical ESBL (n = 93) and ACBL (n = 88)-producing Klebsiella were isolated significantly more (P < 0·05) from companion animals than household animals. Majority of the Klebsiella possessed bla_CTX-M-15 . The sequences bla_CTX-M-15.2 , bla_CTX-M-197 and bla_CTX-M-225 are reported first time from the companion animals. All ACBL-producing isolates possessed bla_AmpC . The present study detected 65·8% of Klebsiella strains as biofilm producers possessing the studied biofilm associated genes. The isolates showed phenotypical resistance against chloramphenicol, tetracycline, doxycycline, co-trimoxazole, ampicillin, cefotaxime/clavulanic acid. The present study showed that companion and household animals (dogs, cats, sheep, goats) may act as a carrier of ESBL/biofilm-producing, multi-drug resistant, high-risk clonal lineage of Klebsiella.

Characterizing Emerging Canine H3 Influenza Viruses

The continual emergence of novel influenza A strains from non-human hosts requires constant vigilance and the need for ongoing research to identify strains that may pose a human public health risk. Since 1999, canine H3 influenza A viruses (CIVs) have caused many thousands or millions of respiratory infections in dogs in the United States. While no human infections with CIVs have been reported to date, these viruses could pose a zoonotic risk. In these studies, the National Institutes of Allergy and Infectious Diseases (NIAID) Centers of Excellence for Influenza Research and Surveillance (CEIRS) network collaboratively demonstrated that CIVs replicated in some primary human cells and transmitted effectively in mammalian models. While people born after 1970 had little or no pre-existing humoral immunity against CIVs, the viruses were sensitive to existing antivirals and we identified a panel of H3 cross-reactive human monoclonal antibodies (hmAbs) that could have prophylactic and/or therapeutic value. Our data predict these CIVs posed a low risk to humans. Importantly, we showed that the CEIRS network could work together to provide basic research information important for characterizing emerging influenza viruses, although there were valuable lessons learned.

Are thalassemia patients oxidatively challenged?

Background

Repeated blood transfusions is the mainstay of treatment for beta thalassemia major patients. Multiple blood transfusions lead to significant iron overload in these patients. Iron overload causes liberation of oxygen free radicals and peroxidative lipid injury. This study has been designed to study whether thalassemics suffer from oxidative injury. It also aims to study the quantum of oxidative injury.

Methods

It is a cross sectional study using cases and controls. Thirty thalassemic patients receiving multiple blood transfusions were included in this study and thirty healthy age and sex matched controls were recruited for the study. Serum ferritin levels, malondialdehyde, nitric oxide levels were estimated.

Results

Levels of all the three parameters were significantly increased (p < 0.05) in the cases compared to controls. Mean levels of all three parameters were correlated with serum ferritin levels and number of blood transfusions in increasing order. All the parameters showed fair degree of correlation (r ≥ 0.25, p ≤ 0.05).

Conclusion

Thalassemic patients receiving multiple blood transfusion suffer from iron overload which results in increased oxidative stress.

Measuring the Severity of Respiratory Illness in the First 2 Years of Life in Preterm and Term Infants

OBJECTIVE

To develop a valid research tool to measure infant respiratory illness severity using parent-reported symptoms.

STUDY DESIGN

Nose and throat swabs were collected monthly for 1 year and during respiratory illnesses for 2 years in a prospective study of term and preterm infants in the Prematurity, Respiratory Outcomes, Immune System and Microbiome study. Viral pathogens were detected using Taqman Array Cards. Parents recorded symptoms during respiratory illnesses using a Childhood Origins of Asthma (COAST) scorecard. The COAST score was validated using linear mixed effects regression modeling to evaluate associations with hospitalization and specific infections. A data-driven method was also used to compute symptom weights and derive a new score, the Infant Research Respiratory Infection Severity Score (IRRISS). Linear mixed effects regression modeling was repeated with the IRRISS illness data.

RESULTS

From April 2013 to April 2017, 50 term, 40 late preterm, and 28 extremely low gestational age (<29 weeks of gestation) infants had 303 respiratory illness visits with viral testing and parent-reported symptoms. A range of illness severity was described with 39% of illness scores suggestive of severe disease. Both the COAST score and IRRISS were associated with respiratory syncytial virus infection and hospitalization. Gestational age and human rhinovirus infection were inversely associated with both scoring systems. The IRRISS and COAST scores were highly correlated (r = 0.93; P < .0001).

CONCLUSIONS

Using parent-reported symptoms, we validated the COAST score as a measure of respiratory illness severity in infants. The new IRRISS score performed as well as the COAST score.

Characterization of beta-lactamase and biofilm producing Enterobacteriaceae isolated from organized and backyard farm ducks

This study was undertaken to detect the occurrence of beta-lactamase and biofilm producing Enterobacteriaceae in healthy ducks. A total 202 cloacal swabs were collected from ducks kept in organized (n = 92) and backyard (n = 110) farms in West Bengal (India). The ducks had no history of antibiotic intake. Among the 87 phenotypically beta-lactamase producing Escherichia coli, 19 (17·43%), 6 (5·05%) and 15 (13·76%) isolates possessed bla_TEM , bla_SHV and bla_CTX-M respectively. Whereas, 5 (38·46%) Salmonella isolates were found to harbour bla_CTX-M . In K. pneumoniae 10 (33·33%), 3 (13·33%), 4 (13·33%) isolates possessed bla_TEM , bla_SHV and bla_CTX-M respectively. The sequences of selected PCR products were found 98% cognate with bla_CTX-M-9, bla_SHV-12 and bla_TEM-1 . Beta-lactamase producing E. coli isolates belonged to 14 different serogroups such as O1, O2, O3, O5, O7, O8, O35, O83, O84, O88, O119, O128, O145 and O157. Moreover, 87 E. coli (79·82%), six Samonella (46·15%) and 13 K. pneumoniae (43·33%) isolates were detected as AmpC producers possessing bla_AmpC . Majority of E. coli (46·79%), Salmonella (46·15%) and K. pneumoniae (70%) isolates were detected as biofilm producers and possessed the associated genes (csgA, sdiA, rcsA, rpoS). Significantly higher occurrence of beta-lactamase and biofilm producing Enterobacteriaceae isolates was detected in backyard ducks than organized farms. SIGNIFICANCE AND IMPACT OF THE STUDY: Consumption of antibiotic through feed or during therapy is considered as potential reason for generation of antimicrobial resistant bacteria in birds. This study provides valuable evidence that exposure to contaminated environment may be an additional source for generation of antimicrobial resistant bacteria in backyard ducks. The backyard ducks are reared by marginal farmers in India who cannot offer antibiotics to them either through feed or during therapy due to high cost. The study also reveals a significant correlation between biofilm formation and possession of antimicrobial resistance genes in the bacterial isolates from the ducks.

T-Cell Responses in Adults During Natural Respiratory Syncytial Virus Infection

Background

The pathogenesis of respiratory syncytial virus (RSV) in older adults may be due to age-related T-cell immunosenescence. Thus, we evaluated CD4 and CD8 T-cell responses during RSV infection in adults across the age spectrum.

Methods

Peripheral blood mononuclear cells collected during RSV infection in adults, age 26-96 years, were stimulated with live RSV and peptide pools representing F, M, NP, and G proteins and analyzed by flow cytometry.

Results

There were no significant age-related differences in frequency of CD4+ T cells synthesizing interferon (IFN)γ, interleukin (IL)2, IL4, IL10, or tumor necrosis factor (TNF)α or in CD8+IFNγ+ T cells. IL4+CD4+ T-cell numbers were low, as were IL13 and IL17 responses. However, in univariate analysis, CD4 T-cell IFNγ, IL2, IL4, IL10, and TNFα responses and CD8+IFNγ+ T cells were significantly increased with more severe illness requiring hospitalization. In multivariate analysis, viral load was also associated with increased T-cell responses.

Conclusions

We found no evidence of diminished RSV-specific CD4 or CD8 T-cell responses in adults infected with RSV. However, adults with severe disease seemed to have more robust CD4 and CD8 T-cell responses during infection, suggesting that disease severity may have a greater association with T-cell responses than age.

Variability of the EG95 antigen-coding gene of Echinococcus granulosus in animal and human origin: implications for vaccine development

In the present study, the genetic variability of the EG95 protein-coding gene in several animal and human isolates of Echinococcus granulosus was investigated. A total of 24 isolates collected from cattle, buffalo, sheep, goat, dog and man were amplified by Eg95-coding gene-specific primers. From the generated sequence information, a conceptual amino acid sequence was deduced. Phylogenetically, the Eg95 coding gene belongs to the Eg95-1/Eg95-2/Eg95-3/Eg95-4 cluster. Further confirmation on the maximum composite likelihood analysis revealed that the overall transition/transversion bias was 2.913. This finding indicated thatthere is bias towards transitional and transversional substitution. Using artificial neural networks, a B-cell epitope was predicted on primary sequence information. Stretches of amino acid residues varied between animal and human isolates when hydrophobicity was considered. Flexibility also varied between larval and adult stages of the organism. This observation is important to develop vaccines. However, cytotoxic T-lymphocyte epitopes on primary sequence data remained constant in all isolates. In this study, agretope identification started with hydrophobic amino acids. Amino acids with the same physico-chemical properties were present in the middle. The conformational propensity of the Eg95-coding gene of 156 amino acid residues had α-turns and β-turns, and α-amphipathic regions up to 129, 138-156 and 151-155 residues, respectively. The results indicated potential T-cell antigenic sites. The overall Tajima's D value was negative (-2.404165), indicative of negative selection pressure.

Effect of CoFe dusting layer and annealing on the magnetic properties of sputtered Ta/W/CoFeB/CoFe/MgO layer structures

We explored the effect of a CoFe wedge inserted as a dusting layer (0.2 nm-0.4 nm thick) at the CoFeB/MgO interface of a sputtered Ta(2 nm)/W(3 nm)/CoFeB(0.9 nm)/MgO(3 nm)/Ta(2 nm) film-a typical structure for spin-orbit torque devices. Films were annealed at temperatures varying between 300 °C and 400 °C in an argon environment. Ferromagnetic resonance studies and vibrating sample magnetometry measurements were carried out to estimate the effective anisotropy field, the Gilbert damping, the saturation magnetization and the dead layer thickness as a function of the CoFe thickness and across several annealing temperatures. While the as-deposited films present only easy-plane anisotropy, a transition along the wedge from in-plane to out-of-plane was observed across several annealing temperatures, with evidence of a spin-reorientation transition separating the two regions.

Neonatal gut and respiratory microbiota: coordinated development through time and space

BACKGROUND

Postnatal development of early life microbiota influences immunity, metabolism, neurodevelopment, and infant health. Microbiome development occurs at multiple body sites, with distinct community compositions and functions. Associations between microbiota at multiple sites represent an unexplored influence on the infant microbiome. Here, we examined co-occurrence patterns of gut and respiratory microbiota in pre- and full-term infants over the first year of life, a period critical to neonatal development.

RESULTS

Gut and respiratory microbiota collected as longitudinal rectal, throat, and nasal samples from 38 pre-term and 44 full-term infants were first clustered into community state types (CSTs) on the basis of their compositional profiles. Multiple methods were used to relate the occurrence of CSTs to temporal microbiota development and measures of infant maturity, including gestational age (GA) at birth, week of life (WOL), and post-menstrual age (PMA). Manifestation of CSTs followed one of three patterns with respect to infant maturity: (1) chronological, with CST occurrence frequency solely a function of post-natal age (WOL), (2) idiosyncratic to maturity at birth, with the interval of CST occurrence dependent on infant post-natal age but the frequency of occurrence dependent on GA at birth, and (3) convergent, in which CSTs appear first in infants of greater maturity at birth, with occurrence frequency in pre-terms converging after a post-natal interval proportional to pre-maturity. The composition of CSTs was highly dissimilar between different body sites, but the CST of any one body site was highly predictive of the CSTs at other body sites. There were significant associations between the abundance of individual taxa at each body site and the CSTs of the other body sites, which persisted after stringent control for the non-linear effects of infant maturity. Canonical correlations exist between the microbiota composition at each pair of body sites, with the strongest correlations between proximal locations.

CONCLUSION

These findings suggest that early microbiota is shaped by neonatal innate and adaptive developmental responses. Temporal progression of CST occurrence is influenced by infant maturity at birth and post-natal age. Significant associations of microbiota across body sites reveal distal connections and coordinated development of the infant microbial ecosystem.

Metamagnetic transition and observation of spin-fluctuations in the antiferromagnetic Heusler compound Pd2MnIn

We report detailed investigations on the structural, magnetic, magneto-transport and calorimetric aspects of a partially ordered Heusler compound Pd₂MnIn. The sample shows antiferomagnetic (AFM) state below around 120 K, though positive paramagnetic Curie temperature signifies a complex magnetic ground state with the presence of both ferromagnetic (FM) and AFM correlations. A clear spin-flop type metamagnetic transition is observed as evident from the magnetization and resistivity data. However, non-saturation of magnetization even at 145 kOe of applied field implies that the high field state may be a spin canted state, originating from the enhanced FM correlations by field induced conduction electron spin polarization. The sample shows a profound quadratic temperature dependence of resistivity below about 20-25 K indicating a spin-fluctuation dominated low temperature region. Previous electronic structure calculations show the existence of a subtle balance between superexchange mediated AFM state and an RKKY (Ruderman-Kittel-Kasuya-Yoshida) interaction mediated FM state in Pd₂MnIn. Such competing AFM-FM correlations can be accounted for the observed spin fluctuations.