Organisational challenges to wellbeing in nuclear medicine technologists: Professionalism, burnout and pragmatic growth

INTRODUCTION

Occupational risk for burnout in nuclear medicine technologists globally, and particularly during disaster demands on the profession, is poorly researched. This idiographic study explored the lived experience of nuclear medicine technologists during COVID-19 in a regional city in Australia.

METHODS

Data was collected from five participants using semi-structured interviews and transcribed and analysed according to the protocols of Interpretative Phenomenological Analysis (IPA).

RESULTS

Four group experiential themes were identified: Systemic Contraindications, Professional Strengths and Limitations, Pragmatic Growth, and Covid Rollercoaster. For these participants a dichotomous health care system, impacted by COVID-19, risked career longevity and burnout. Through empathic connection with vulnerable patients, they redefined their priorities, re-engaged in supportive connections with colleagues, and sought new pathways.

CONCLUSION

Multiple workplace stressors compounded by COVID-19, risked mental wellbeing, in these participants. Nevertheless, these challenges provided opportunities for reflection around career trajectory and longevity precipitating personal growth, job satisfaction and work-life balance.

IMPLICATIONS FOR PRACTICE

This study provided a lens on the risk factors inherent for nuclear medicine technologists in Australia, exacerbated by the COVID-19 pandemic. Current, and disaster protective practices, to ensure wellbeing and prevent burnout risk are recommended for future research.

Binding of Per- and Polyfluoroalkyl Substances (PFAS) to the PPARγ/RXRα-DNA Complex

Nuclear receptors are the fundamental building blocks of gene expression regulation and the focus of many drug targets. While binding to DNA, nuclear receptors act as transcription factors, governing a multitude of functions in the human body. Peroxisome proliferator-activator receptor γ (PPARγ) and the retinoid X receptor α (RXRα) form heterodimers with unique properties and have a primordial role in insulin sensitization. This PPARγ/RXRα heterodimer has been shown to be impacted by per- and polyfluoroalkyl substances (PFAS) and linked to a variety of significant health conditions in humans. Herein, a selection of the most common PFAS (legacy and emerging) was studied utilizing molecular dynamics simulations for PPARγ/RXRα. The local and global structural effects of PFAS binding on the known ligand binding pockets of PPARγ and RXRα as well as the DNA binding domain (DBD) of RXRα were inspected. The binding free energies were predicted computationally and were compared between the different binding pockets. In addition, two electronic structure approaches were utilized to model the interaction of PFAS within the DNA binding domain, density functional theory (DFT) and domain-based pair natural orbital coupled cluster with perturbative triples (DLPNO-CCSD(T)) approaches, with implicit solvation. Residue decomposition and hydrogen-bonding analysis were also performed, detailing the role of prominent residues in molecular recognition. The role of l-carnitine is explored as a potential in vivo remediation strategy for PFAS interaction with the PPARγ/RXRα heterodimer. In this work, it was found that PFAS can bind and act as agonists for all of the investigated pockets. For the first time in the literature, PFAS are postulated to bind to the DNA binding domain in a nonspecific manner. In addition, for the PPARγ ligand binding domain, l-carnitine shows promise in replacing smaller PFAS from the pocket.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Isolation and functional characterization of novel isoprene synthase from Artocarpus heterophyllus (jackfruit)

Isoprene, a Natural Volatile Organic Compound (NVOC) is one of the chief by-products of plant metabolism with important applications in the synthesis of rubber and pharmaceuticals as a platform molecule. Isoprene was obtained earlier from petroleum sources; however, to synthesise it new fermentation-based strategies are being adopted. Bioinformatics tools were utilised to isolate the Isoprene Synthase (IspS) gene which converts the precursors Isopentenyl Diphosphate (IPP) and Dimethylallyl Diphosphate (DMAPP) into isoprene. Metabolic engineering strategies were to synthesise an isoprene-producing recombinant clone derived from Artocarpus heterophyllus (jackfruit). The functional characterization was done using the overexpression of the isoprene synthase gene in an Escherichia coli BL21 host. The recombinant clone, ISPS_GBL_001 (submitted to GenBank, National Centre for Biotechnology Information or NCBI) was used for fermentation in the batch and fed-batch mode to produce isoprene. Isoprene productivity of 0.08 g/g dextrose was obtained via the fed-batch mode maintaining the process parameters at optimum. The quantification and confirmation of isoprene was done using gas chromatography (GC) and GC-mass spectrometry (GC-MS) of the extracted sample, respectively. This study makes significant contribution to the ongoing research on bio-isoprene synthesis by highlighting a novel plant source of the IspS gene followed by, its successful expression in a recombinant host, validated by fermentation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03441-7.

577. Cord Blood Protective Antibodies Seroprevalence against Diphtheria, Pertussis, Measles, Mumps and Rubella at Birth among Healthy Term Indian Neonates

Background

The resurgence of vaccine preventable diseases in young infants is a matter of concern worldwide. Cord blood antibodies seroprevalence against various vaccine preventable diseases could reflect protection rates among adults, which could be important in providing protection in early infancy of newborn baby. Tdap vaccination is not yet part of immunization program for pregnant women in India.

Methods

Apparently healthy term newborns, delivered at a tertiary care hospital in Northern India, over two-year period were enrolled after taking informed written consent from their parents, and their cord blood sample was collected at birth. Ethical clearance was obtained from Institute Ethics Committee before starting enrollment.

Results

A total of 160 newborns (M:F=86:74) were enrolled. In our study, antibodies (IgG) against diphtheria toxin (DT) were >0.1 IU/ml in 44.4% (71/160), 0.01 to 0.1 IU/ml in 53.1% (85/160) and < 0.01 IU/ml in 2.5% (4/160). Only 44.4% of them were fully protected at birth against diphtheria.

Antibodies (IgG) against pertussis toxin (PT) >40 U/ml were seen in 41.2% (66/160). Out of these 66 children, 23 had titers >100 U/ml. Total of 58.8% (94/160) children had antibodies < 40 U/ml. Out of these 94 children, 48 had titers < 20 U/ml. Since correlates of protection in pertussis are not defined; those having titers >100 U/ml i.e. 14.3% were most protected; while those having titers < 20 U/ml were least protected.

Antibodies (IgG) against measles antigen were >12 IU/ml in 88.8% (142/160). Antibodies (IgG) against mumps antigen were >12 IU/ml in 83.1% (133/160). Antibodies (IgG) against rubella antigen were >12 IU/ml in 83.7% (134/160).

Conclusion

Protective antibodies against diphtheria and pertussis toxins were less in the studied newborns at birth making them susceptible to these diseases in early infancy, before primary vaccination commences. Tdap vaccination for pregnant mothers in India could help in improving these titers and protection in early infancy. Protective antibodies against measles, mumps and rubella in studied newborns at birth were satisfactory. For further enhancing protection, especially against rubella, one dose of MMR vaccine may be advised for women in child bearing age.

Acknowledgement: PGI Intramural Research Grant

Disclosures

All Authors: No reported disclosures.

Effectiveness and Durability of COVID-19 Vaccination in 9447 Patients With IBD: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

The serological responses after severe acute respiratory syndrome coronavirus 2 vaccination may be attenuated in immunocompromised individuals. The study aimed to systematically evaluate the seroconversion rates after complete vaccination for coronavirus disease 2019 (COVID-19) in patients with inflammatory bowel disease (IBD).

METHODS

Electronic databases were searched to identify studies reporting response to COVID-19 vaccination in IBD. Pooled seroconversion rates after complete vaccination were calculated. Subgroup analysis for vaccine types was also performed. Pooled seroconversion rates for various drugs or classes were also estimated. The pooled rates of breakthrough infections in vaccinated IBD patients were estimated. The pooled neutralization rates after complete vaccination were also estimated. The studies reporting durability of titers were systematically assessed.

RESULTS

A total of 46 studies were included. The pooled seroconversion rate for complete vaccination (31 studies, 9447 patients) was 0.96 (95% confidence interval [CI], 0.94-0.97; I2 = 90%). When compared with healthy control subjects, the pooled relative risk of seroconversion was lower (0.98; 95% CI, 0.98-0.99; I2 = 39%). The pooled seroconversion rates were statistically similar among various drug classes. The pooled positivity of neutralization assays (8 studies, 771 participants) was 0.80 (95% CI, 0.70-0.87; I2 = 82%). The pooled relative risk of breakthrough infections in vaccinated IBD patients was similar to vaccinated control subjects (0.60; 95% CI, 0.25-1.42; I2 = 79%). Most studies suggested that titers fall after 4 weeks of COVID-19 vaccination, and the decay was higher in patients on anti-tumor necrosis factor alone or combination with immunomodulators. An additional dose of COVID-19 vaccine elicited serological response in most nonresponders to complete vaccination.

CONCLUSIONS

Complete COVID-19 vaccination is associated with seroconversion in most patients with IBD. The decay in titers over time necessitates consideration of additional doses in these patients.

P-478 Deleterious influence of cyclophosphamide on primordial follicles derives from increased DNA damage and reduced proliferation in xenotransplanted human ovarian tissue

Study question

What are the acute effects of cyclophosphamide (Cp) on primordial follicles (PrFs) in human ovarian tissue?

Summary answer

Administration of Cp damages PrFs via DNA fragmentation and results in reduced proliferation with no increase in PrF activation markers.

What is known already

Alkylating agents are highly gonadotoxic, and in cases where freezing oocytes, embryos, or ovarian tissue is impractical, a better understanding of the underlying damage mechanism could enable development of fertoprotective approaches (1). Studies from different groups suggest conflicting mechanisms of ovarian damage, with either PrF activation (2) or cell damage and apoptosis (3-4) proposed as drivers of PrF depletion. Few studies have examined this question using human tissue. We performed xenografts using ovarian tissue from a 17-month-old girl to ensure a graft with plentiful PrFs to test the acute effect of Cp.

Study design, size, duration

Cross-sectional study.

We utilized a xenotransplantation model in which human ovarian tissue is co-transplanted with endothelial cells (ECs) into immunocompromised mice (NSG) (5). Three weeks after xenotransplantation, time 0, intraperitoneal (IP) injection of (saline/Cp) was followed by an IP injection of ethynyl-deoxyuridine (Edu), at 0 and 24 hours, followed by 5-chloro-2′-deoxyuridine (CldU), at 48 and 72 hours. Grafts were harvested at 96 hours.

Participants/materials, setting, methods

We co-xenotransplanted human ovarian cortical tissue from a 17-month-old girl, cryopreserved for fertility preservation, into immunocompromised mice. After 3 weeks, Cp (75mg/Kg)/saline was administered IP. Mice were then sequentially injected with EdU, followed by CldU (both at 100mg/kg for 2 days) 24 hours apart. Twenty-four hours later, mice were sacrificed and xenografts were harvested and sectioned. Slides were stained for EdU, CldU, VASA, γ-H2AX, FOXO3a, and 4',6-Diamidino-2-Phenylindole-Dilactate (DAPI) and imaged using a confocal microscope.

Main results and the role of chance

We used anti-VASA staining to evaluate oocyte morphology, confirming that chemotherapy was not sterilizing; we counted 76.5% of morphologically normal PrF in the control group (Ctrl) (130/170) and 35.1% (13/37) in the Cp group. In the Ctrl group, 11% stained positively for DNA fragmentation using anti-γ-H2AX, whereas 43% were positive in the Cp group (p = 0.0073). To evaluate activation, we stained for FOXO3a in the oocyte nucleus. No difference was found between the groups: 52.4% (74/144) versus 44.6% (37/83) in Ctrl versus Cp, respectively. Interestingly, when comparing EdU incorporation, the Ctrl group had higher incorporation at 72%, versus the Cp group with 40% of incorporation (p = 0.0485), and no difference was found with CldU incorporation: Ctrl 22% versus 27% in the Cp group, respectively (P = 0.6960).

Limitations, reasons for caution

We measured acute effects, DNA fragmentation, and proliferation, at five days post-Cp administration; however, this falls short of evaluating processes that appear later (fibrosis and neovascularization). Also, the results may partly stem from the patient’s young age. Repeating the experiment using adult-derived tissue might yield different results.

Wider implications of the findings

A better understanding of both the timeline and underlying mechanisms that contribute to chemotherapy-related gonadotoxicity could diminish the damage and depletion of the ovarian reserve (PrF). These results provide evidence that direct damage to PrFs, and not increased activation, contributes to gonadotoxicity in the acute phase following administration of Cp.

Trial registration number

NA

Safety of SARS-CoV-2 vaccination in patients with inflammatory bowel disease: A systematic review and meta-analysis

INTRODUCTION

Risk of adverse effects and flare of inflammatory bowel disease (IBD) are frequently cited reasons for COVID-19 vaccine hesitancy.

METHODS

Electronic databases were searched to identify studies reporting the use of COVID-19 vaccine in IBD. We selected studies reporting the incidence of various adverse effects (local or systemic) and flares of IBD after COVID-19 vaccination. The pooled incidence rates for various adverse effects, stratified for the dose and the type of vaccine (adenoviral or mRNA) were estimated.

RESULTS

Nine studies (16 vaccination cohorts) were included. The pooled incidence rate of overall adverse events was 0.55 (95%CI, 0.45-0.64, I²= 95%). The pooled incidence rate of local adverse events was 0.64 (0.47-0.78, I²= 100%). The pooled incidence rates of fatigue, headache, myalgia, fever and chills were 0.30 (0.21-0.40, I²= 99%), 0.23 (0.17-0.30, I²= 99%), 0.18 (0.13-0.24, I²= 99%), 0.10 (0.06-0.17, I²= 98%) and 0.15 (0.06-0.3, I²= 86%), respectively. The pooled incidence rates of severe adverse events, adverse events requiring hospitalization and flares of IBD following COVID-19 vaccination were 0.02 (0.00-0.12, I²= 97%), 0.00 (0.00-0.01, I²= 27%) and 0.01 (0.01-0.03, I²= 45%), respectively.

CONCLUSION

COVID-19 vaccination in patients with IBD appears to be safe with only mild adverse events. Flares of IBD and severe adverse events requiring hospitalization were infrequent.

Endoscopic Ultrasound-guided Drainage of Patients With Infected Walled-off Necrosis: Which Stent to Choose?

BACKGROUND

Endoscopic ultrasound (EUS)-guided drainage is the preferred treatment of pancreatic fluid collections (PFC). However, the choice of the stent for EUS-guided drainage in critically ill PFC cases with infected walled-off necrosis (WON) and/or organ failure (OF) remains unknown.

MATERIALS AND METHODS

Between January 2018 and December 2019, consecutive patients with symptomatic PFC subjected to EUS-guided drainage using biflanged metal stents (BFMS) or double-pigtail plastic stents (DPPS) were compared for technical success, clinical success, duration of the procedure, need for intensive care unit stay, duration of intensive care unit stay, ventilator need, resolution of OF, the duration for resolution of OF, complications, need for salvage percutaneous drainage or surgery and mortality. A subgroup of patients having infected WON with/without OF were analyzed separately.

RESULTS

Among 120 patients (84.6% males) with PFC (108 WON, 22 pseudocyst) who underwent EUS-guided drainage, there was no difference in outcome parameters in BFMS and DPPS groups. Among patients with WON, clinical success was significantly higher (96.2% vs. 81.8%, P=0.04), with significantly shorter hospital stay (6 vs. 10 d) and procedure duration (17.18±4.6 vs. 43.6±9.7 min, P<0.0001) in the BFMS group. Among patients with infected WON with/without OF, the clinical success was significantly higher (100% vs. 73.9%, P=0.02), and the duration of the procedure was significantly lower (16.28±4.4 vs. 44.39±10.7, P<0.0001) in BFMS compared with DPPS group.

CONCLUSION

EUS-guided drainage of WON using BFMS scores over DPPS. In patients having infected WON with/without OF, BFMS may be preferred over DPPS.

737 STOOLS FOR STOOLS - COMBINING MEDICAL AND CONSERVATIVE TREATMENTS TO REDUCE CONSTIPATION IN THE ELDERLY INPATIENT POPULATION

Introduction

Constipation is a common cause of morbidity in the elderly. Its management is particularly challenging in the inpatient population, where many factors exacerbate constipation. We describe a Quality Improvement Project to reduce the rates of constipation on a female Medicine for the Elderly ward.

Aims

Our aim was to increase bowel chart documentation (nursing and doctor entries) and increase patient frequency of bowel motions to at least once every two days. In particular we focused on conservative measures such as the use of footstools to optimise posture when using commodes and toilets [R Hari Krishnan, Proc Inst Mech Eng H, 2019, 233(4):464–475].

Method

• Weekly monitoring of ward inpatients. • Measurements taken were: days since last bowel motion, laxatives prescribed, bowel chart and ward round documentation, and episodes of diarrhoea over the past week. • One episode of diarrhoea was defined as 3 motions of type 6 or type 7 stool in 24 hours. • A new intervention was introduced every two weeks, over a total of 2 months. Interventions: 1. Recording bowel motions at the daily ‘Board Round’ Multi-Disciplinary Meeting. 2. Ward staff education sessions. 3. Footstools for use with commodes and toilets. 4. High-fibre foods to patients with constipation.

Results

Level of constipation was successfully reduced, with 100% patients moving bowels every 2 days from a baseline of 68%. Ward round and bowel chart documentation improved to 100% and 93.3% respectively (from 41.3% and 33.3%). However, incidence of diarrhoea increased from 0 episodes/week to 8 episodes/week, with laxative prescriptions similarly increased from 50% to 86%.

Conclusion

Constipation improved with our interventions, but at the unintended cost of laxative-associated diarrhoea. Our next steps will be to reduce laxative prescriptions in favour of conservative measures, in order to reduce episodes of loose stool while maintaining our improved constipation rates.

A reassessment of TBT action levels for determining the fate of dredged sediments in the United Kingdom

As part of reviewing the United Kingdom (UK) action levels (ALs) of contaminants for managing the disposal of dredged marine sediment material, tributyl tin (TBT) has been reassessed. TBT is a banned biocide capable of causing severe harm to the marine environment. Its presence is routinely screened for prior to marine disposal of dredged sediment material. Dredged sediment TBT concentrations have been studied using UK monitoring data obtained between 2000 and 2018. The changes in these TBT concentrations have guided the reassessment of ALs. Recent toxicity studies have also guided the reassessment of TBT ALs. This study, which itself forms part of a larger review by the Department for Environment, Food and Rural Affairs, has concluded that current UK TBT ALs may no longer be fit for purpose. A more environmentally protective approach for controlling release of TBT into the marine environment is recommended.

The sensitivity and specificity of rotational thromboelastometry (ROTEM) to detect coagulopathy during moderate and severe postpartum haemorrhage: a prospective observational study

INTRODUCTION

Point-of-care viscoelastic haemostatic assays such as rotational thromboelastometry (including ROTEM and TEG) have been used in the management of postpartum haemorrhage (PPH). This study compared results obtained from the automated ROTEM Sigma with laboratory tests of coagulation and platelet count during PPH.

METHODS

A prospective observational cohort study recruited women with PPH ≥1000 mL (or clinical concern of bleeding). The Fibtem A5, Extem CT and Pltem (Extem A5 - Fibtem A5) results were compared with laboratory tests of fibrinogen, prothrombin time (PT), activated partial thromboplastin time (APTT) and platelet count.

RESULTS

521 women were recruited, including 274/277 (98.9%) of women with PPH ≥1500 mL. Fibtem A5 results were matched with laboratory fibrinogen in 552/644 (85.7%) samples. The incidence of abnormal laboratory results was low: fibrinogen ≤2 g/L 23/464 (5.0%), PT or APTT >1.5 × midpoint of reference range 4/464 (0.9%), and platelet count <75 × 10⁹/L 11/477 (2.3%). Area-under- the-receiver operator characteristic curve for Fibtem A5 to detect fibrinogen ≤2 g/L was 0.96 (95% Confidence Intervals (CI) 0.94 to 0.98, P<0.001), with sensitivity and specificity of Fibtem A5 ≤11 mm to detect fibrinogen ≤2 g/L of 0.76 and 0.96. Prolonged Extem CT results improved after treatment of hypofibrinogenaemia alone. Intervention points for platelet and fresh frozen plasma (FFP) transfusion based on ROTEM Sigma parameters could not be established.

CONCLUSION

During PPH (≥1000 mL or cases of clinical concern about bleeding), ROTEM Sigma Fibtem A5 can detect fibrinogen ≤2 g/L and guide targeted fibrinogen replacement. Laboratory results should continue to be used to guide platelet and FFP transfusion.

Utility of viscoelastography with TEG 6s to direct management of haemostasis during obstetric haemorrhage: a prospective observational study

BACKGROUND

The TEG 6s is an automated cartridge-based device with limited description of use in obstetric haemorrhage. The aim of this analysis was to describe the utility of TEG 6s in identifying abnormal laboratory results of coagulation and platelet count, and inform an interventional treatment algorithm for postpartum haemorrhage.

METHODS

A prospective observational cohort study of 521 women with moderate to severe obstetric haemorrhage (>1000 mL blood loss), including 372 women with at least one TEG 6s test. A non-pregnant control group was used for reference. TEG 6s test parameters Citrated Functional Fibrinogen (CFF), Citrated Kaolin TEG (CK) and Citrated Rapid TEG (CRT) were compared with paired laboratory tests of fibrinogen, PT/aPTT and platelet count, obtained during haemorrhage.

RESULTS

Among 456 TEG 6s tests, 389 were matched with laboratory coagulation results. The receiver operator characteristic area-under-the-curve (95% CI) for CFF amplitude by 10 min to detect Clauss fibrinogen ≤2 g/L was 0.95 (0.91 to 0.99) (P<0.0001, sensitivity 0.74 and specificity 0.97 at ≤17 mm). False positives had median (IQR) Clauss fibrinogen of 2.4 (2.3-2.7) g/L. The CK-R time had some utility for detecting prolonged PT/aPTT, however a threshold for fresh frozen plasma transfusion was not established. A CRT maximum amplitude <57 mm, when CFF was ≥15 mm, identified four of eight samples with platelet count <75 × 10⁹/L.

CONCLUSION

The TEG 6s CFF can be used to identify low fibrinogen during obstetric haemorrhage. A value to identify transfusion thresholds for PT/aPTT and platelets was not established, and laboratory results should continue to be used.

469 Evaluating the Use of Laparoscopic-Assisted Gastrostomy Tube Insertion in Children with Epidermolysis Bullosa: A Retrospective Observational Study

Introduction

Nutritional management of children with epidermolysis bullosa (EB) presents multiple challenges including reduced oral intake and mucosal fragility. Laparoscopic-assisted gastrostomy (LAG) tube feeding is effective in improving nutritional status. We aim to review the effectiveness and morbidity of our minimally invasive laparoscopic-assisted approach in EB patients.

Method

A retrospective, observational cohort study was conducted on all EB patients who underwent LAG tube insertion between 2009 and 2019. Patient demographics, admission details and 12-month clinical outcomes were reported.

Results

31 EB patients underwent LAG placement. Median age at insertion was 7.2 (IQR ± 6.5) years, with 8 (25.8%) and 3 (9.7%) of patients requiring oesophageal dilatation and fundoplication, respectively. 71.4% patients experienced minor complications including: overgranulation (35.7%), gastrostomy infection (32.1%), pain (21.4%), mild gastrostomy leakage (17.9%), blockage (10.7%) and late displacement (3.6%). 6 patients (21.4%) developed major complications with extensive gastrostomy site leakage. Only one patient required laparoscopic refashioning for stoma prolapse six years post-insertion. No cases of gastrostomy-related mortality were recorded and an improvement in both mean weight and height Z-scores was observed.

Conclusions

LAG is well-tolerated in EB patients with improvements in growth and minimal morbidity 12-months post-gastrostomy insertion. An extended follow-up period is required to ascertain long-term impacts of gastrostomy feeding.

Evidence that ageing does not influence the uniformity of the muscle-tendon unit adaptation in master sprinters

Differences in the adaptation processes between muscle and tendon in response to mechanical loading can lead to non-uniform mechanical properties within the muscle-tendon unit (MTU), potentially increasing injury risk. The current study analysed the mechanical properties of the triceps surae (TS) MTU in 10 young (YS; 22 ± 3 yrs) and 10 older (OS; age 65 ± 8 yrs; i.e. master) (inter)national level sprinters and 11 young recreationally active adults (YC; 23 ± 3 yrs) to detect possible non-uniformities in muscle and tendon adaptation due to habitual mechanical loading and ageing. Triceps surae muscle strength, tendon stiffness and maximal tendon strain were assessed in both legs during maximal voluntary isometric plantarflexion contractions via dynamometry and ultrasonography. Irrespective of the leg, OS and YC in comparison to YS demonstrated significantly (P < 0.05) lower TS muscle strength and tendon stiffness, with no differences between OS and YC. Furthermore, no group differences were detected in the maximal tendon strain (average of both legs: OS 3.7 ± 0.8%, YC 4.4 ± 0.8% and YS 4.3 ± 0.9%) as well as in the inter-limb symmetry indexes in muscle strength, tendon stiffness and maximal tendon strain (range across groups: -5.8 to 4.9%; negative value reflects higher value for the non-preferred leg). Thus, the findings provide no clear evidence for a disruption in the TS MTU uniformity in master sprinters, demonstrating that ageing tendons can maintain their integrity to meet the increased functional demand due to elite sports.

Ibrutinib in combination with nab-paclitaxel and gemcitabine for first-line treatment of patients with metastatic pancreatic adenocarcinoma: phase III RESOLVE study

BACKGROUND

First-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC) includes nab-paclitaxel/gemcitabine. Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumor activity through tumor microenvironment modulation. The safety and efficacy of first-line ibrutinib plus nab-paclitaxel/gemcitabine treatment in patients with PDAC were evaluated.

PATIENTS AND METHODS

RESOLVE (NCT02436668) was a phase III, randomized, double-blind, placebo-controlled study. Patients (histologically-confirmed PDAC; stage IV diagnosis ≥6 weeks of randomization; Karnofsky performance score ≥70) were randomized to once-daily oral ibrutinib (560 mg) or placebo plus nab-paclitaxel (125 mg/m²) and gemcitabine (1000 mg/m²). Primary endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS); overall response rate and safety were assessed.

RESULTS

In total, 424 patients were randomized (ibrutinib arm, n = 211; placebo arm, n = 213). Baseline characteristics were balanced across arms. After a median follow-up of 25 months, there was no significant difference in OS between ibrutinib plus nab-paclitaxel/gemcitabine versus placebo plus nab-paclitaxel/gemcitabine (median of 9.7 versus 10.8 months; P = 0.3225). PFS was shorter for ibrutinib plus nab-paclitaxel/gemcitabine compared with placebo plus nab-paclitaxel/gemcitabine (median 5.3 versus 6.0 months; P < 0.0001). Overall response rates were 29% and 42%, respectively (P = 0.0058). Patients in the ibrutinib arm had less time on treatment and received lower cumulative doses for all agents compared with the placebo arm. The most common grade ≥3 adverse events for ibrutinib versus placebo arms included neutropenia (24% versus 35%), peripheral sensory neuropathy (17% versus 8%), and anemia (16% versus 17%). Primary reasons for any treatment discontinuation were disease progression and adverse events.

CONCLUSIONS

Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with PDAC. Safety was consistent with known profiles for these agents.

Safety of tapentadol compared with other opioids in chronic pain treatment: network meta-analysis of randomized controlled and withdrawal trials

OBJECTIVE

To assess the relative safety of oral tapentadol PR and other opioid analgesics for moderate or severe chronic pain in adults, we conducted a systematic review and network meta-analysis (NMA).

METHODS

A systematic review was conducted to identify randomized controlled trials (RCTs) and randomized withdrawal trials of tapentadol with other WHO stage II and III opioid analgesics in patients with moderate or severe chronic pain. Searches were conducted in MEDLINE, EMBASE, PubMed, Cochrane databases and trial registries. Feasibility assessment evaluated the trials' suitability for NMA. Outcomes assessed were overall AEs, overall serious adverse events, constipation, nausea, dizziness, somnolence, headache, and discontinuation due to AEs. Randomized withdrawal trials were analyzed separately to other RCTs.

RESULTS

Searches conducted in April 2019 identified 16,604 records. Following screening and feasibility assessment, 29 RCTs and 19 randomized withdrawal trials were identified and included in the NMA. Consistent with existing research, evidence from RCTs suggested that tapentadol is associated with relatively lower odds of adverse events occurring than most active comparators. The withdrawal trial data were less clear, with higher uncertainty around the results, and results that appear to contradict the RCT evidence. There are a number of trial design factors that may be affecting these results.

CONCLUSIONS

RCT evidence suggests that tapentadol can be a useful treatment option for patients suffering from chronic pain and in need of an opioid analgesic. Opioids should be prescribed by a qualified physician only after other analgesics have been considered, taking side effects and misuse risk into account.

Risk scoring for time to end-stage knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

This study constructs a risk score for patients' progression to end-stage knee osteoarthritis (OA) within 4 years.

DESIGN

The Osteoarthritis Initiative (OAI) was a longitudinal study of the onset and progression of knee OA. Using a recent definition of end-stage knee OA, we implement interval-censored survival forests to select predictors of this endpoint. We fit an interval-censored Cox model for time to end-stage knee OA, using the selected predictors. The risk score is the Cox model's fitted linear combination of the nine selected baseline structural and symptomatic knee OA variables.

RESULTS

We fit our models on a training set of 2,701 patients, and we evaluate on an independent test set of 1,436 patients. On the test sample, we observe a concordance index of 0.86 between risk score and time to end-stage, AUC of 0.87 for predicting end-stage within 24, 36, and 48 months, and positive predictive values that increase with the risk score. This risk stratification algorithm could enrich clinical trial patient enrollment. By enrolling test sample patients with scores above a threshold, a trial could have included 91% of test set patients who reach end-stage within 4 years while only enrolling 45% of the test sample.

CONCLUSION

Using statistical methods, we construct and validate an interpretable risk score for time to end-stage knee OA. This score can help disease-modifying OA treatment developers to select candidates with the highest risk of fast-progressing knee OA.

Introduction of standardized, cumulative quantitative measurement of blood loss into routine maternity care

Introduction: Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity in the UK. Visual estimation of blood loss is unreliable yet remains common practice. As part of a national quality improvement project to improve care during PPH, standardized, quantitative measurement of blood loss (QBL) for all deliveries was introduced into a tertiary obstetric unit in Cardiff, Wales.Methods: Retrospective analysis of 875 consecutive maternities between December 2017 and February 2018 was undertaken. Of these, 372 mothers had both pre- and post-partum hemoglobin (Hb) were recorded. Regression analyses were performed to investigate the relationship between change in Hb adjusted for red cell transfusion and QBL.Results: The correlation coefficient between QBL and adjusted change in Hb for all deliveries (n = 372) was 0.57. This corresponded to an estimated fall of adjusted change in Hb of 15.3 g/L (95% CI: 13.1, 17.6) per 1000 mL blood loss.Discussion: QBL has been shown to be reliable across all maternity settings, with reproducible results in theater and delivery rooms (on the obstetric unit and alongside midwifery-led unit). QBL is moderately correlated with adjusted change in Hb for all volumes of bleeding and gives clinicians more accurate knowledge of blood loss than visual estimation. This low-cost, low-fidelity intervention can influence the timely escalation of clinical care and therefore patient outcome.

Calibration of polyvinylidene fluoride based dust detectors in response to varying grain density and incidence angle

Permanently polarized Polyvinylidene Fluoride (PVDF) films have been used on a variety of spacecraft as in situ dust detectors to measure the size and spatial distributions of micron and sub-micron dust particles. The detectors produce a short electric pulse when impacted by a hypervelocity dust particle. The pulse amplitude depends on the mass and relative speed of the dust grain. This relationship has been studied both empirically and numerically to better understand the film's principle of operation, as well as the effects of film thickness, film temperature, and particle penetration depth. However, little work has been done to constrain the effects of varying particle density and incidence angle despite the frequent occurrence of such configurations in most space-based applications. We present calibrations of non-penetrating impacts on 28 μm thick films at varying incidence angles ranging from 0° to 75° for iron and aluminum particles in the mass and speed range of 10^-12 ≤ m ≤ 10^-8 g and 0.5 ≤ v ≤ 7 km/s, respectively. The study was carried out at the 3 MV dust accelerator laboratory at the University of Colorado at Boulder. The results show that PVDF signals are largely independent of particle density and incidence angle up to 75° for non-penetrating impacts.

Cord Blood Antibody Seroprevalance Against Diphtheria, Pertussis, Measles, Mumps and Rubella among Term Healthy Indian Newborns

Background

The resurgence of vaccine preventable diseases in young infants is a matter of concern worldwide. The aim of our study was to determine the seroprevalance of protective antibodies against diphtheria, pertussis, measles, mumps and rubella antigens in cord blood among term Indian newborns, at birth.

Methods

Apparently healthy term newborns, delivered at a tertiary care hospital in Northern India, over two year period (Apr 15-March 17) were enrolled after taking informed written consent from their parents; and their cord blood sample was collected. Ethical clearance was obtained from Institute Ethics committee, before enrolling subjects. Cord blood samples were tested for antibodies using commercial ELISA kits IMMUNOLAB IgG.

Results

A total of 160 newborns (M:F = 86:74) were enrolled. In our study, antibodies (IgG) against diphtheria toxin (DT) were > 0.1 IU/mL in 44.4% (71/160), 0.01 to 0.1 IU/mL in 53.1% (85/160) and < 0.01 IU/mL in 2.5% (4/160). None of their mothers received Tdap vaccine in past. Antibodies (IgG) against pertussis toxin (PT) > 40 U/mL were seen in 41.2% (66/160). Out of these 66 children, 23 had titres > 100 U/mL. Total of 58.8% (94/160) children had antibodies < 40 U/mL. Out of these 94 children, 48 had titers < 20 U/mL.

Antibodies (IgG) against measles antigen were > 12 IU/mL in 88.8% (142/160). A total of 11.2 (18/160) had titers below 12 IU/mL. Out of these 18 children, 5 had titers < 6 IU/mL. Antibodies (IgG) against mumps antigen were > 12 IU/mL in 83.1% (133/160). A total of 16.9% (27/160) had titers below 12 IU/mL. Out of these 27 children, 12 had titers < 6 IU/mL. Antibodies (IgG) against rubella antigen were > 12 IU/mL in 83.7% (134/160). A total of 16.3% (26/160) had titers below 12 IU/mL. Out of these 26 children, 22 had titers < 6 IU/mL.

Conclusion

Only 44.4% of studied newborns were fully protected (> 0.1 IU/mL) against diphtheria, because of maternal antibodies. As correlates of protection for pertussis are not yet defined; those having anti-PT titers >100 IU/mL i.e., 14.3% (23/160) were most protected; while those having titers < 20 U/mL i.e., 30% (48/160) were least protected. Out of studied newborns, fully protected (>12 IU/mL) against measles, mumps and rubella were 88.8%, 83.1% and 83.7% respectively.

Acknowledgement. PGI Intramural research grant

Disclosures

All authors: No reported disclosures.

Four-dimensional (4D) tracking of high-temperature microparticles

High-speed tracking of hot and molten microparticles in motion provides rich information about burning plasmas in magnetic fusion. An exploding-wire apparatus is used to produce moving high-temperature metallic microparticles and to develop four-dimensional (4D) or time-resolved 3D particle tracking techniques. The pinhole camera model and algorithms developed for computer vision are used for scene calibration and 4D reconstructions. 3D positions and velocities are then derived for different microparticles. Velocity resolution approaches 0.1 m/s by using the local constant velocity approximation.

Nanoparticle Trapping and Characterization Using Open Microcavities

Characterization and trapping of nanoparticles in solution is of great importance for lab-on-a-chip applications in biomedical, environmental, and materials sciences. Devices are now starting to emerge allowing such manipulations and investigations in real-time. Better insights into the interaction between the nanoparticle and the optical trap is therefore necessary in order to move forward in this field. In this work, we present a new kind of nanotweezers based on open microcavities. We show that by monitoring the cavity mode wavelength shift as the particle diffuses through the cavity, it is possible to establish both the nanoparticle polarizability and its coefficient of friction. Additionally, our experiment provides a deep insight in the interaction between the nanoparticle and the cavity mode. The technique has built-in calibration of the trap strength and spring constant, making it attractive for practical applications. This work illustrates the potential of such optical microcavities for future developments in nanoparticle sensors and lab-on-a-chip devices.