Involvement of PD-1+CD4+ T cells in the development of traumatic tracheal stenosis by regulating the IL-17/STAT3 pathway

Studies have highlighted an upregulation of PD-1 expression in CD4+ T cells, which accelerates lung fibrosis by activating the IL-17/STAT3 pathway, leading to IL-17A and TGF-β1 secretion. However, the relation with traumatic tracheal stenosis (TS) remains unexplored. Our analysis found significant increases in PD-1+CD4+ T cells, IL-17A, and TGF-β1 in the TS patients (n = 10). The cellular model used CD4+ T cells co-cultured with bronchial fibroblasts while the animal model used a nylon brush to scrape the damaged tracheal mucosa. Interventions with PD-1 and STAT3 inhibitors both in vivo (n = 5) and in vitro (n = 6) showed decreased expression of TGF-β1 and IL-17A in CD4+ T cells, decreased collagen I synthesis in vivo, and reduced tractal fibrosis in vitro. Furthermore, PD-1's modulation of the STAT3 was evident. This research unveils PD-1+CD4+ T cells' role in TS, thus suggesting a novel immunotherapeutic strategy to counteract tracheal fibrosis.

Surgical resection of primary intracardiac sarcomas and outcomes: A review of case reports over 20 years

Objective

A quarter of all cardiac tumors are malignant, and most (~ 95%) are sarcomas. It is the most aggressive malignant cardiac tumor carrying the worst prognosis. Tumor involvement with the vital intracardiac structures makes it difficult for complete surgical resection. We aimed to study the role of complete surgical resection and its importance in long-term outcomes.

Methods

We analyzed published literature from 2002 to 2022 using PubMed. Cases reported adult, intracardiac sarcomas, and received surgical resections were included. We reviewed 132 published case reports, including and analyzed the following variables: demographics, clinical presentations, diagnostic imaging modality, the extent of surgical resection, pathological diagnosis, tumor location, postoperative chemo-radiation therapy, and follow-up (including re-operation, local and distant recurrence).

Results

A total of 135 patients are included from 132 articles. The mean age was 46.69 (18-86) and 76 patients were females. The main complaints were dyspnea (70%) and chest pain (32%). Performed investigations were transthoracic echocardiography (TTE) in 114/135 (84%), computer tomography (CT) scan 89/135 (66%), trans-esophageal echocardiography (TOE) 22%, and cardiac magnetic resonance imaging (MRI) 29%. The most common location was the atrium (left 46%, right 30%). Complete surgical resection was performed in 91 cases (67%), and frozen section was performed in 62 patients (43 positives). Incomplete resections were in 42 cases. Patients who underwent complete surgical resection had mean survival of 14.58 months and median of 10.5 months, compared to incomplete resection patients with 9.12 months and 6.5 months respectively.

Conclusion

Our review shows complete surgical resection results in better short- and long-term outcomes in intracardiac sarcoma patients. Furthermore, combining chemo-radiotherapy has additional benefits towards long-term survival.

Latitudinal patterns in stabilizing density dependence of forest communities

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10-12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests.

Tropical tree ectomycorrhiza are distributed independently of soil nutrients

Mycorrhizae, a form of plant-fungal symbioses, mediate vegetation impacts on ecosystem functioning. Climatic effects on decomposition and soil quality are suggested to drive mycorrhizal distributions, with arbuscular mycorrhizal plants prevailing in low-latitude/high-soil-quality areas and ectomycorrhizal (EcM) plants in high-latitude/low-soil-quality areas. However, these generalizations, based on coarse-resolution data, obscure finer-scale variations and result in high uncertainties in the predicted distributions of mycorrhizal types and their drivers. Using data from 31 lowland tropical forests, both at a coarse scale (mean-plot-level data) and fine scale (20 × 20 metres from a subset of 16 sites), we demonstrate that the distribution and abundance of EcM-associated trees are independent of soil quality. Resource exchange differences among mycorrhizal partners, stemming from diverse evolutionary origins of mycorrhizal fungi, may decouple soil fertility from the advantage provided by mycorrhizal associations. Additionally, distinct historical biogeographies and diversification patterns have led to differences in forest composition and nutrient-acquisition strategies across three major tropical regions. Notably, Africa and Asia's lowland tropical forests have abundant EcM trees, whereas they are relatively scarce in lowland neotropical forests. A greater understanding of the functional biology of mycorrhizal symbiosis is required, especially in the lowland tropics, to overcome biases from assuming similarity to temperate and boreal regions.

Intraocular pressure measurements in paediatric glaucoma: A narrative review on accuracy, tolerability, and ease of use

INTRODUCTION

Numerous tonometers are available to measure intraocular pressure (IOP) in children with glaucoma. This review aims to discuss IOP measurement techniques and principles and compare the accuracy, tolerability and ease of use of available tonometers in measuring IOP in paediatric glaucoma patients.

MATERIALS AND METHODS

A review of observational studies was conducted to discuss the accuracy, tolerability and ease of use of tonometers in measuring IOP in children with glaucoma.

RESULTS

Goldmann applanation tonometry (GAT) and its portable handheld versions remain the gold standard in measuring IOP. Tono-Pen (Reichert Ophthalmic Instruments, Depew, New York, USA) and rebound tonometer (RBT) both correlate well with GAT. Although both tonometers tend to overestimate IOP, Tono-Pen overestimates more than RBT. Overestimation is more remarkable in higher IOP and corneal pathologies (such as but not limited to scarred cornea and denser corneal opacity). RBT was better tolerated than other tonometers in children and was easier to use in children of all ages.

CONCLUSIONS

RBT is the preferred tonometer for measuring IOP in children with glaucoma, as it is less traumatic, time efficient and does not require fluorescein dye or anaesthesia. However, examiners should use a second tonometer to confirm elevated IOP readings from the RBT.

Inhibition of the membrane repair protein annexin-A2 prevents tumor invasion and metastasis

Cancer cells are exposed to major compressive and shearing forces during invasion and metastasis, leading to extensive plasma membrane damage. To survive this mechanical stress, they need to repair membrane injury efficiently. Targeting the membrane repair machinery is thus potentially a new way to prevent invasion and metastasis. We show here that annexin-A2 (ANXA2) is required for membrane repair in invasive breast and pancreatic cancer cells. Mechanistically, we show by fluorescence and electron microscopy that cells fail to reseal shear-stress damaged membrane when ANXA2 is silenced or the protein is inhibited with neutralizing antibody. Silencing of ANXA2 has no effect on proliferation in vitro, and may even accelerate migration in wound healing assays, but reduces tumor cell dissemination in both mice and zebrafish. We expect that inhibiting membrane repair will be particularly effective in aggressive, poor prognosis tumors because they rely on the membrane repair machinery to survive membrane damage during tumor invasion and metastasis. This could be achieved either with anti-ANXA2 antibodies, which have been shown to inhibit metastasis of breast and pancreatic cancer cells, or with small molecule drugs.

Fish and Food-Fatale: Food-borne Trematode Opisthorchis viverrini and Cholangiocarcinoma

Neglected Tropical Diseases (NTDs) are a group of communicable diseases with a long history with human beings. NTDs are the proxy of poverty since they affect those in low-income and extreme-poverty populations, as those populations lack access to proper health care, clean water, sanitary conditions, and hygiene. NTDs create losses for a nation that come from the health and the economic sectors as well since the costs of diagnosis, prevention, and treatment strain the national purse strings. One of the 20 different forms of NTDs on the list is food-borne trematodes, comprises of Fasciola, Paragonimus, Clonorchis, and Opisthorchis. Currently, it is estimated that food-borne trematodes can cause a devastating effect on mortality and morbidity. All of them are zoonotic, as humans become infected by ingestion of a second intermediate host, such as freshwater snails, fish, or water vegetables. Opisthorchis viverrini, one of the food-borne trematodes that can be found mostly in South East Asia regions, especially in the Mekong basin, is regarded as a group 1 carcinogen leading to cholangiocarcinoma (CCA). This study aims to present the updated review of Opisthorchis viverrini and CCA.

The diagnostic role of preoperative blood tests in complicated appendicitis: A feasible approach to surgical decision

Background

An accurate diagnosis and timely surgical intervention have significant importance in noncomplicated appendicitis (NCA) and complicated appendicitis (CA). Therefore, any factor that helps in the prediction of CA also contributes to suitable treatment options.

Aim

This retrospective study aimed to identify any relationship between acute appendicitis (AA) and preoperative blood test levels and whether these parameters can differentiate between NCA and CA patients.

Patients and Methods

A database of 201 appendectomies and 100 control healthy patients was analyzed between 2019 and 2022. Patients were divided into three groups: NCA without peritonitis or phlegmonous appendicitis as group 1; CA with perforated, necrotizing appendicitis with peritonitis as group 2; and the healthy control group (CG) as group 3. White blood cell (WBC), platelet distribution width (PDW), mean platelet volume (MPV), red cell distribution width (RDW), creatine kinase (CK), and bilirubin levels were collected from the patients and compared statistically between the groups.

Results

Age, WBC, and PDW levels were set as predictive in the differential diagnosis of CA as a result of receiver operating characteristic (ROC) analysis. The multivariate analysis demonstrated that age (OR: 1.023; 95% CI: 1.000-1.045; P = 0.04), male sex (OR: 3.718; 95% CI: 1.501-9.213; P = 0.005), WBC levels (OR: 1.000; 95% CI: 1.000-1.000; P = 0.002), and PDW levels (OR: 2.129; 95% CI: 1.301-3.484; P = 0.003) were independently associated with CA.

Conclusion

Age, higher WBC count, and PDW levels are valuable in differentiating the diagnosis of CA from NCA, and this could be a feasible approach for surgical decisions.

Same-day discharge (SDD) vs standard enhanced recovery after surgery (ERAS) protocols for major colorectal surgery: a systematic review

BACKGROUND

Enhanced recovery after surgery (ERAS) programs are well-established, resulting in improved outcomes and shorter length of hospital stay (LOS). Same-day discharge (SDD), or "hyper-ERAS", is a natural progression of ERAS. This systematic review aims to compare the safety and efficacy of SDD against conventional ERAS in colorectal surgery.

METHODS

The protocol was prospectively registered in PROSPERO (394793). A systematic search was performed in major databases to identify relevant articles, and a narrative systematic review was performed. Primary outcomes were readmission rates and length of hospital stay (LOS). Secondary outcomes were operative time and blood loss, postoperative pain, morbidity, nausea or vomiting, and patient satisfaction. Risks of bias was assessed using the ROBINS-I tool.

RESULTS

Thirteen studies were included, with five single-arm and eight comparative studies, of which one was a randomised controlled trial. This comprised a total of 38,854 patients (SDD: 1622; ERAS: 37,232). Of the 1622 patients on the SDD pathway, 1590 patients (98%) were successfully discharged within 24 h of surgery. While most studies had an overall low risk of bias, there was considerable variability in inclusion criteria, types of surgery or anaesthesia, and discharge criteria. SDD resulted in a significantly reduced postoperative LOS, without increasing risk of 30-day readmission. Intraoperative blood loss and postoperative morbidity rates were comparable between both groups. Operative duration was shorter in the SDD group. Patient-reported satisfaction was high in the SDD cohort.

CONCLUSION

SDD protocols appear to be safe and feasible in selected patients undergoing major colorectal operations. Randomised controlled trials are necessary to further substantiate these findings.

Amplification of a terahertz wave via stimulated Raman scattering

Extremely strong terahertz (THz) waves are desperately demanded for investigating nonlinear physics, spectroscopy, and imaging in the THz range. However, traditional crystal-/semiconductor-based THz sources have limitations of reaching extremely high amplitude due to the damage threshold of devices. Here, by introducing Raman amplification to the THz range, we propose a novel, to the best of our knowledge, scheme to amplify THz waves in plasma. A long-pulse CO₂ pump laser transfers its energy to a multicycle, 10-THz seed in a two-step plasma. By one-dimensional simulations, a 0.87-GV/m, 1.2-ps-duration THz seed is amplified to 10 GV/m in a 5.7-mm-long plasma with an amplification efficiency approaching 1%. The method provides a new technology to manipulate the intensity of THz waves.

Diagnostic Performance of High-Resolution Vessel Wall MR Imaging Combined with TOF-MRA in the Follow-up of Intracranial Vertebrobasilar Dissecting Aneurysms after Reconstructive Endovascular Treatment

BACKGROUND AND PURPOSE

Few studies have reported the utility of high-resolution vessel wall MR imaging in the follow-up of endovascularly treated vertebrobasilar dissecting aneurysms. This study aimed to evaluate the diagnostic performance of high-resolution vessel wall MR imaging combined with TOF-MRA in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.

MATERIALS AND METHODS

Patients with intracranial vertebrobasilar dissecting aneurysms with reconstructive endovascular treatment and followed up with TOF-MRA, high-resolution vessel wall MR imaging, and DSA were included. With DSA as the criterion standard, the diagnostic performance of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA in the evaluation of aneurysm occlusion status and parent artery patency was assessed. Visualization of the stented artery on TOF-MRA and high-resolution vessel wall MR imaging was rated on a 5-point scale.

RESULTS

Twenty-seven patients with 29 aneurysms were included. The sensitivity, specificity, positive predictive value, and negative predictive value of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA for diagnosing aneurysm remnants were 80.0%, 100.0%, 100.0%, and 82.4%; 53.3%, 100.0%, 100.0%, and 66.7%; and 93.3%, 100.0%, 100.0%, and 93.3%, respectively. For the visualization of the stented artery, the mean score of high-resolution vessel wall MR imaging was significantly higher than that of TOF-MRA (4.88 [SD, 0.32] versus 2.53 [SD, 1.25], P < .001). In the evaluation of parent artery patency (normal or pathologic), whereas TOF-MRA had a sensitivity, specificity, positive predictive value, and negative predictive value of 100.0%, 8.0%, 14.8%, and 100.0%, respectively, high-resolution vessel wall MR imaging was completely consistent with the DSA.

CONCLUSIONS

High-resolution vessel wall MR imaging combined with TOF-MRA at 3T showed good diagnostic performance in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.

Quality Improvement at the Laboratory’s Specimen Reception Station

Introduction/Objective

In our 1000-bed acute care tertiary hospital, physicians order laboratory tests via the computerized-provider-order-entry (CPOE) system and print barcode labels (patient demographics/tests ordered) at the computer-on-wheel printer. When tubes with unsuitable barcodes (misaligned, poor quality) are received at the laboratory specimen reception area a fresh barcode is re-printed by our laboratory staff. An incident involving a re- printed barcode label pasted on the wrong blood tube prompted an investigation into the quality of barcodes.

Methods/Case Report

We initiated ‘an opportunity for improvement (OFI) project’ at the laboratory specimen reception station. The OFI team involved Nursing, Information Technology (IT) and Pathology departments aimed to eliminate re-printing of barcode labels by 75% within 6 months. We collated and analyzed reasons for re-printing of barcodes on 3 separate 48-hour periods (27-28 April 2020, 24-25 June 2020, and 13-14 June 2022). A series of interventions and initiatives were implemented.

Results (if a Case Study enter NA)

Re-printed barcodes were from the Emergency Department (56%), Out-patient clinics (7%) and Wards (57%). Root cause analysis(RCA) using the “5 whys” technique categorized re-print causes into staff-related (misaligned barcodes) and printer-related (faint barcodes lines/truncated un-verifiable patient demographics). The team mass-emailed clinicians an educational “Do-You-Know” guide on proper pasting of barcodes on blood tubes and instructions on how to obtain help for printer rectification. These guide documents were placed in the hospital-wide document-sharing portal - Docupedia. Immediate close follow-up with sites that had poor barcodes was done in real-time. Barcode reprints decreased 83% within 2 months - from 174 (27-28 Apr 2020) to 30 (24-25 Jun 2020). A recent audit showed sustained elimination of barcode re-printing: 25 cases (13-14 Jun 2022).

Conclusion

The OFI project has successfully raised the quality of CPOE labels on specimen tubes contributing to process efficiency and safer patient care. Close communication with all care sites and their representatives on the OFI team are critical success factors.

Assessment of optimal thresholds for ventricular scar substrate characterization using the high density grid multipolar mapping catheter

Funding Acknowledgements

Type of funding sources: None.

Background

Voltage thresholds for ventricular scar definition are based on historic data collected using catheters with widely spaced bipoles in the absence of contact force. Modern multipolar mapping catheters employ smaller electrodes and interelectrode spacing that theoretically allows for mapping with increased resolution and reduced far-field electrogram (EGM) component. Despite the advancement in technology, historic cut-offs of &lt;0.5mV for dense scar and 0.5-1.5mV for scar borderzone continue to be used in contemporary electrophysiology.

Purpose

We aimed to assess the optimal voltage cut-offs for ventricular scar substrate characterization using the HD Grid multipolar mapping catheter. Voltage cut-offs were assessed against cardiac MRI derived scar. We compared optimal voltage cut-offs using conventional bipolar sampling, the Best Duplicate Algorithm and with the HD wave solution plus best duplicate algorithm on.

Methods

A multicentre study of twenty patients undergoing VT ablation was conducted. Substrate mapping was performed using the high-density HD-grid multipolar mapping catheter. Bipolar voltage maps were co-registered with cardiac MRI obtained prior to the procedure to assess the voltage characteristics of scar defined by cardiac MRI (CMR) (Figure 1). Pre-procedure contrast enhanced CMR data were analysed using ADAS software (Galgo medical). Data points were collected in regions of scar during (1) HD wave mapping with best duplicate algorithm on(Waveon), (2) Mapping with HD wave off and best duplicate on (Waveoff) and (3) with conventional bipolar mapping (Alloff).

Results

The median bipolar voltage for regions of dense CMR scar using (Waveon) HD wave solution and best duplicate algorithm was 0.27mV (IQR 0.14 – 0.46). The median voltage with (Waveoff) HD wave off was 0.29mV (0.15 – 0.45). The median voltage with (Alloff) HD wave off and best duplicate off was 0.32mV (0.19 – 0.5). ROC analysis using AUC suggested the optimal cut-off for endocardial dense scar using (Waveon) HD wave mapping and best duplicate algorithm was 0.30mV (sensitivity: 69.6%, specificity: 60.74%), (Waveoff) cut-off with the best duplicate and without the HD wave mapping was 0.34mV (sensitivity: 69.78%, specificity: 64.46%) and (Alloff) without wave mapping or best duplication was 0.36mV (sensitivity: 84%, specificity: 52%) Figure 2.

Conclusion

Ventricular substrate characterization with newer mapping technology using narrow electrode spacing and smaller electrode size suggests that traditional voltage cut-offs may need revision for delineation of scar characteristics. Additionally, the ability to repeat sample in a region to obtain the best signal (Best Duplicate), and the ability to obviate the effect of wavefront direction using the HD wave solution omnipolar technology, may further increase the fidelity of scar characterization. This has important implications for mapping VT and characterizing channels in order to identify VT circuits.

Integration of structural and functional data in VT ablation -- SENSE2 protocol mapping

Funding Acknowledgements

Type of funding sources: None.

Background

We have previously developed the sense protocol functional substrate mapping technique for VT ablation(1). However, functional substrate characterizaiton can involve protracted mapping time.

Purpose

We incorporated the integration of MRI data using ADAS-3D software into the mapping workflow, to integrate structural mapping information into the functional mapping substrate characterization, in order to improve procedural efficiency.

Methods

CMRs were performed in 20 patients with ischemic related VT and VT therapy in the previous 6 months. These were processed with the ADAS-3D software to characterize the extent of ventricular scars and also ADAS corridors which may correlate with VT channels. Focused substrate maps were then performed in patients, guided by the extent of ADAS scar and corridors, looking at the scar substrate in intrinsic rhythm and then functional channels using single extra pacing from the RV at 20ms above ERP (SENSE2 Protocol). Specifically healthy areas 2cm beyond the scar borderzone based on ADAS were not mapped, in order to reduce substrate mapping time and complete geometries were not created. Following delineation of functional channels pacemapping and entrainment mapping were used to confirm targets for ablation.

The ADAS 3D MRI was integrated into the into the VT substrate map on Ensite-Precision with alignment to the aorta, RV and PA (Figure 1). We compared our data with previous functional mapping data without the integration of MRI.

Results

20 patients (age 70 years; 19 male subjects) underwent ablation. Mean EF 28%. Median procedure time was 161 minutes compared with 246 minutes (in our previous study)(p=&lt;0.001) Mean substrate mapping time was 32 mins vs 63 mins (p=&lt;0.001). Mean ablation time was 22 mins vs 32 mins (p=0.11). 85% (17 of 20) patients were free from symptomatic VT/ anti-tachycardia pacing or implantable cardioverter defibrillator shocks at a median follow-up of 171 days. The mean VT burden was reduced from 22 events per patient in the 6 months’ pre-ablation to 1 event per patient in the median follow up period of 171 days post ablation (p=0.02). Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same time period(p=0.03).

Conclusion

The SENSE2 protocol involves the integration of structural and functional data into the VT workflow for substrate characterization. It enables focused substrate maps to be performed without the need for complete geometry to be created in large ventricles. Outcomes compare favourably with our previous data but with significantly shorter procedure times. This streamlined workflow has the potential to improve care in VT ablation by shortening procedure times with similar outcomes which may reduce risks for the patient.

Figure 1: Comparison of Voltage Map with MRI scar & corridors using ADAS

Demographic composition, not demographic diversity, predicts biomass and turnover across temperate and tropical forests

The growth and survival of individual trees determine the physical structure of a forest with important consequences for forest function. However, given the diversity of tree species and forest biomes, quantifying the multitude of demographic strategies within and across forests and the way that they translate into forest structure and function remains a significant challenge. Here, we quantify the demographic rates of 1961 tree species from temperate and tropical forests and evaluate how demographic diversity (DD) and demographic composition (DC) differ across forests, and how these differences in demography relate to species richness, aboveground biomass (AGB), and carbon residence time. We find wide variation in DD and DC across forest plots, patterns that are not explained by species richness or climate variables alone. There is no evidence that DD has an effect on either AGB or carbon residence time. Rather, the DC of forests, specifically the relative abundance of large statured species, predicted both biomass and carbon residence time. Our results demonstrate the distinct DCs of globally distributed forests, reflecting biogeography, recent history, and current plot conditions. Linking the DC of forests to resilience or vulnerability to climate change, will improve the precision and accuracy of predictions of future forest composition, structure, and function.

Pigment concentrations in eggshell and their related gene expressions in uterus of Changshun blue eggshell chickens

1. The goal of this study was to investigate the colour diversity of egg shells and expression of related genes in the uterus of chickens that produce eggs of different colours.2. Four colour types of Changshun blue-shell chickens, producing dark or light blue, greenish-brown and brown shelled eggs, were selected. The eggshell pigment concentration and colour values in each group were examined. The relative gene expression of solute carrier organic anion transporter family member 1C1 (SLCO1C1), ferrochelatase (FECH), haem oxygenase 1 (HO-1), ovotransferrin (OF) and biliverdin reductase A (BLVRA) in eggshell gland were measured.3. The Δb, ΔE and protoporphyrin in brown and greenish-brown groups were significantly higher in the blue egg group (P < 0.01), whereas ΔL was significantly lower than that in the blue eggs (P < 0.01). There was no significant difference in biliverdin concentration between the brown and blue groups.4. The Δa values, in descending order, were 8.27 ± 2.76 in the brown, -3.79 ± 2.39 in the greenish-brown and -7.29 ± 2.27 in the blue groups, respectively. The relative expression of HO-1 in the greenish-brown and light blue groups was significantly higher than in the dark blue and brown groups. The relative expression of FECH in the light blue group was significantly lower than that in the dark blue, greenish-brown or brown group (P < 0.01). The relative expression of HO-1 and BLVRA genes in the dark blue group was significantly higher than that in the light blue, greenish-brown and the brown group (P < 0.01).5. The Δa might provide a better index than protoporphyrin and biliverdin contents for eggshell colour breeding. Overall, HO-1 as well as BLVRA were important candidate genes for the selection of dark blue eggs.

Long term prognostic utility of exercise capacity in renal transplant candidates

Background

Pharmacological stress testing is commonly performed for cardiovascular risk stratification in potential renal transplant candidates due to a perceived inability for these patients to exercise. We have previously reported that exercise stress testing is feasible in renal transplant candidates but the prognostic utility of exercise capacity in this patient group is not known.

Purpose

This study prospectively evaluated the effect of exercise capacity on the risk of major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal myocardial infarction, and stroke, in renal transplant candidates undergoing exercise stress echocardiography (ESE) for pre-transplant cardiovascular assessment.

Methods

We evaluated 898 consecutive patients with chronic kidney disease stage 4/5 who underwent symptom-limited treadmill ESE over 5-year mean follow-up. Exercise capacity was measured by age and sex predicted metabolic equivalents (METs). The primary outcome was achievement of predicted METs with first MACE. Cox proportional hazard multivariable modelling was used to determine MACE predictors with transplantation treated as a time-varying covariate. We also performed secondary analysis using a 7 MET threshold.

Results

There were 106 MACE with an annual cumulative risk of 2.4%. During follow-up, 525 (58%) received transplantation. Achievement of predicted METs (48%) (hazard ratio (HR) 0.49, 95% confidence interval (CI) 0.29–0.82, p=0.007) and transplantation (HR 0.52, 95% CI 0.30–0.91, p=0.02) were independently associated with reduced MACE. Similar results were observed using a 7 MET threshold achieved by 734 (82%) patients. Patients achieving predicted METs had no difference in MACE regardless of subsequent transplantation (HR 0.78, 95% CI 0.32–1.92, p=0.59). Patients who achieved predicted METs and did not receive transplantation had similar outcomes to those that did not achieve predicted METs and received transplantation (HR 0.97, 95% CI 0.42–2.25, p=0.95).

Conclusions

Exercise capacity is associated with reduced long-term MACE in renal transplant candidates undergoing ESE for pre-transplant cardiovascular assessment. Achievement of age and sex predicted METs confers excellent prognosis independent of subsequent transplantation.

Funding Acknowledgement

Type of funding sources: None.

Assessing learner engagement with virtual educational events: Development of the Virtual In-Class Engagement Measure (VIEM)

BACKGROUND

The COVID-19 pandemic has necessitated virtual education, but effects on learner engagement are unknown. We developed a virtual in-class engagement measure (VIEM) to assess learner engagement in online surgical education events.

METHODS

Using the STROBE, an observer collected tool to document student engagement, as a template an ASE committee workgroup developed the VIEM. The VIEM had two parts: observer assessment and learner self-assessment of engagement. Trained observers collected engagement data from two institutions using the VIEM. Surgical attendings, fellows and residents were observed during virtual learning events. Educator attitudes towards online teaching were also assessed via survey.

RESULTS

22 events with 839 learners were observed. VIEM distinguished between sessions with low and high engagement. 20% of learners pretended to participate. Half of instructors were comfortable with virtual teaching, but only 1/3 believed was as effective as in-person. 2/3 of teachers believed video learners were more engaged than audio learners.

CONCLUSIONS

Virtual platforms do not automatically translate into increased engagement. Standard tools such as VIEM may help with assessment of engagement during virtual education.

P–709 Dual stimulation in-vitro-maturation (Duostim IVM) for overcoming oocyte maturation arrest, resulting in embryo transfer and livebirth

Study question

Does luteal phase followed by follicular phase letrozole priming and dual oocyte retrieval for in-vitro maturation (IVM) overcome oocyte maturation arrest (OMA)?

Summary answer

Oocyte maturation, fertilization,embryo cryopreservation and livebirth can be achieved with letrozole priming IVM in rare cases of OMA.

What is known already

OMA is an intractable problem resulting in only immature oocytes being collected and to date no succesful treatment exists. Attempts to mature oocytes collected in stimulated IVF cycles with OMA have so far failed. Cases with OMA can be due to intrinsic oocyte defects, intrafollicular factors or resistance to stimulation.

Study design, size, duration

Six women with OMA in ≥ 2 prior stimulated IVF cycles were treated between March 2019 and December 2020.

Participants/materials, setting, methods

Participants had total of 18 (range 2 - 6) prior IVF cycles yielding only 166 immature oocytes. Letrozole 5mg was given days 15–18 of ovulatory cycle; SC decapeptyl 0.1mg trigger given at follicles 12 mm, 38 hours&lt;OPU. After menstruation, letrozole 5mg days 3–7; SChCG 250ug when follicles=12 mm 38 hours&lt;OPU. After in-vitro-maturation oocytes reaching MII were fertilized. Embryos from luteal collection were frozen and fresh embryo transfer was attempted after follicular phase collection.

Main results and the role of chance

Six women underwent DuoStim IVM, median (quartiles) 3.5 (0 - 9) GV and 0.5 (0 - 2) MI oocytes were collected from luteal phase OC and 0 (0 - 0) GV and 2(0 – 4.5) MI oocytes were collected from follicular phase OC. They had a total of 166 immature oocytes collected in prior IVF cycles. There were no MII oocytes at the time of collection in any cycles.0 (0 – 3.5) oocytes matured from luteal phase OC and 1 (0 – 4) from follicular phase OC. 0 (0 – 1.5) embryos were available from luteal phase and 0 (0 - 2) from follicular phase OC.Two subjects (29 and 33 years old) underwent fresh DET and the 29 year old with 2 previous failed IVF cycles achieved a livebirth (50% per ET and 16.7% per started cycle). None of the women who did not have an embryo for fresh transfer from the follicular phase collection had an embryo from the luteal phase collection. The same 29 year old has 2 luteal phase and 2 more follicular phase embryos vitrified.

Limitations, reasons for caution

OMA is a rare condition with a variety of etiologies. Different etiologies can require different managements.

Wider implications of the findings: It may be possible to overcome OMA with letrozole IVM in rare cases. This case is the first recorded live birth. The value of dual stimulation overcoming OMA remains uncertain.

Trial registration number

This study is approved by the local ethical commitee of Medicana Samsun International Hospital by a Grant number of 02/05.02.2020: registration is not required due to retrospective status

173 Early Results of a Variable-Angle Volar Locking Plate for Distal Radius Fractures: A Bi-Centre Study

Introduction

This study examines the clinical, functional and radiological outcomes of distal radius fracture fixation with the Aptus® (Medartis, Pennsylvania) locking plate in order to determine its efficacy and to identify notable findings related to treatment variations.

Method

This is a retrospective bi-centre study collecting patient details from a District General Hospital and a Regional Hand Unit. We assessed 61 consecutive patients with distal radius fractures (AO grade A = 19, B = 9, C = 33) fixed using Aptus® plate with a minimum of six months follow-up. Outcome measures included the DASH score, wrist range of movement and grip strength, and complications. Radiographs were reviewed to assess restoration of anatomy and union.

Results

All but two fractures united within six weeks. Mean ranges of movement were only mildly restricted compared to the normal wrist (flexion/extension = 102°; radial/ulna deviation = 53°; pronation/supination = 169°). Mean postoperative grip strength was 23.8kg which was comparable to the contralateral side at 31.5kg. The mean DASH score was 18.2. Seven patients had screws misplaced outside the distal radius although three of these remained asymptomatic.

Conclusions

Variable-angle locking systems benefit from flexibility of implant positioning and may allow enhanced inter-fragmentary reduction for accurate fixation of intra-articular fractures.

P22: CONSERVATIVE MANAGEMENT OF NECK OF FEMUR FRACTURES

Introduction

According to NICE CG124, the gold standard of treatment for neck of femur (NOF) fractures is operative management on the day or day after admission. In practice, this is not always achievable depending on various factors, e.g. patient preference, clinical condition and theatre availability, with a further subset of patients undergoing conservative management.

Method

A retrospective analysis was performed on all NOF fractures managed non-operatively at a single centre from January 2017 to August 2019 by case notes analysis and review of radiographical images. Demographics, fracture type, pre-fracture mobility status, co-morbidities, mortality and Nottingham Hip Fracture Score (NHFS) are reported. Where applicable, our dataset is correlated with the National Hip Fracture Database for comparison.

Result

24 patients were included in the study period, with a mean age of 79.9 years (range 54-99 years) and male:female ratio of 0.85:1. The mean NHFS (n=18) was 5.7 (range 3-8) and at least 62.5% (n=15) were deemed unfit for surgery or arrested pre-operatively. Conservatively managed NOF fractures are associated with a 30-day mortality of 41.7% compared to the centre average of 8.2% and national average of 6.9% for all NOF fractures. Overall mortality within 1 year is 95.5% (n=22).

Conclusion

Our study confirms that the conservative management of NOF fractures is associated with high mortality, however it may be the only treatment option acceptable in patients who are limited by unfavourable clinical conditions. Therefore, the decision for conservative management in NOF fractures requires careful consideration with the need for an established decision-making pathway.

Take-home message

The conservative management of neck of femur fractures is associated with high mortality, therefore requires careful consideration with the need for an established decision-making pathway.

Interactions between all pairs of neighboring trees in 16 forests worldwide reveal details of unique ecological processes in each forest, and provide windows into their evolutionary histories

When Darwin visited the Galapagos archipelago, he observed that, in spite of the islands' physical similarity, members of species that had dispersed to them recently were beginning to diverge from each other. He postulated that these divergences must have resulted primarily from interactions with sets of other species that had also diverged across these otherwise similar islands. By extrapolation, if Darwin is correct, such complex interactions must be driving species divergences across all ecosystems. However, many current general ecological theories that predict observed distributions of species in ecosystems do not take the details of between-species interactions into account. Here we quantify, in sixteen forest diversity plots (FDPs) worldwide, highly significant negative density-dependent (NDD) components of both conspecific and heterospecific between-tree interactions that affect the trees' distributions, growth, recruitment, and mortality. These interactions decline smoothly in significance with increasing physical distance between trees. They also tend to decline in significance with increasing phylogenetic distance between the trees, but each FDP exhibits its own unique pattern of exceptions to this overall decline. Unique patterns of between-species interactions in ecosystems, of the general type that Darwin postulated, are likely to have contributed to the exceptions. We test the power of our null-model method by using a deliberately modified data set, and show that the method easily identifies the modifications. We examine how some of the exceptions, at the Wind River (USA) FDP, reveal new details of a known allelopathic effect of one of the Wind River gymnosperm species. Finally, we explore how similar analyses can be used to investigate details of many types of interactions in these complex ecosystems, and can provide clues to the evolution of these interactions.

[The proatherogenic effect of high salt diet combined with focal hypoperfusion on spontaneous hypertension rat]

Objective: To explore the histopathology, monocytes phenotypes and brain mRNA transcription of angiogenic and atherogenic factors preliminarily in spontaneous hypertensive rats (SHRs) fed with high salt diet and subjected to chronic focal hypoperfusion. Methods: A total of 21 SHRs were randomly assigned into SHR with normal diet (SHR-ND group, n=7), SHR fed with high salt (8%) chows (SHR-HSD group, n=14) groups. After induction of high salt diet for 20 weeks, unilateral carotid artery occlusion was applied to one half of SHR-HSD (SHR-HSD-UCAO, n=7) group for 10 weeks to mimic chronic focal cerebral hypoperfusion. The neuropathology, monocytes phenotypes and brain transcription of fibroblast growth factor (FGF-b), platelet-derived endothelial cell growth factor (PD-ECGF), angiogenin (ANG), transforming growth factor-β (TGF-β) and vascular endothelial growth factor A (VEGF-A) among three groups were compared. Results: The systolic blood pressure ((246±12) mmHg vs (220±16) mmHg, P=0.0291, 1 mmHg=0.133 kPa) and diastolic blood pressure ((189±15) mmHg vs (164±12) mmHg, P=0.0143) of SHR-HSD group were elevated significantly compared with those of SHR-ND group. Compared with normotensive Wistar-Kyoto (WKY), SHR-ND, SHR-HSD and SHR-HSD-UCAO groups demonstrated lipohyalinosis, vessel wall thickening, lumen narrowing and multiple enlarged perivascular space and diffuse disarrangement of nerve fiber and myelin vacuolation in corpus callosum pathologically. The ratio of CD11b(+) CD68(+) monocytes in peripheral blood of SHR-HSD group was higher compared with both SHR-ND and SHR-HSD-UCAO groups (P=0.000 8). The mean inflorescence index (MFI) of CD86 and CD206 showd considerable decline in SHR-HSD-UCAO group compared with those of SHR-HSD group (P=0.018 7 and 0.016 8, respectively). The CD86 MFI of CD11b+CD68+ monocytes in SHR-HSD-UCAO group was remarkably higher than that of SHR-ND and SHR-HSD groups (P=0.000 5). Compared with SHR-ND and SHR-HSD groups, the brain mRNA transcription of angiogenic factors including PD-ECGF and ANG were down-regulated (P=0.004 6 and 0.000 2, respectively), while the atherogenic factors including TGF-β and VEGF-A were up-regulated in SHR-HSD-UCAO group (P<0.000 1 and P=0.045, respectively). Conclusion: SHR-HSD-UCAO group shares the pathophysiological characteristics with advanced stage arteriosclerotic cerebral small vessel disease (aCSVD), including neuropathology, imbalanced circulating monocytes phenotypes and down-regulated angiogenic factors.

The interspecific growth-mortality trade-off is not a general framework for tropical forest community structure

Resource allocation within trees is a zero-sum game. Unavoidable trade-offs dictate that allocation to growth-promoting functions curtails other functions, generating a gradient of investment in growth versus survival along which tree species align, known as the interspecific growth-mortality trade-off. This paradigm is widely accepted but not well established. Using demographic data for 1,111 tree species across ten tropical forests, we tested the generality of the growth-mortality trade-off and evaluated its underlying drivers using two species-specific parameters describing resource allocation strategies: tolerance of resource limitation and responsiveness of allocation to resource access. Globally, a canonical growth-mortality trade-off emerged, but the trade-off was strongly observed only in less disturbance-prone forests, which contained diverse resource allocation strategies. Only half of disturbance-prone forests, which lacked tolerant species, exhibited the trade-off. Supported by a theoretical model, our findings raise questions about whether the growth-mortality trade-off is a universally applicable organizing framework for understanding tropical forest community structure.

Association between prosthesis geometry and leaflet thrombosis following transcatheter aortic valve replacement

Introduction

Leaflet thrombosis (LT) following transcatheter aortic valve replacement (TAVR) is a recognised condition. The association between prosthesis geometry [expansion, implant depth and commissural alignment (CA)] and LT is unclear.

Methods

Patients that received intra-annular TAVR prosthesis and post-procedure computed tomography (CT) with a 320-slice scanner were included. LT, defined as at least 50% restricted leaflet motion, was assessed with a dedicated 3Mensio workstation by two experienced CT readers. Prosthesis expansion was defined as actual divided by expected prosthesis area as a percentage of expected area whilst eccentricity was [(maximum diameter − minimum diameter) / maximum diameter) × 100%], both measured at prosthesis inflow, annulus and outflow. Implant depth was the average distance between prosthesis inflow and nadir of each cusp. CA was the average angle between each native and prosthesis leaflet coaptations. Significant commissural misalignment (CMA) was defined as CA greater than 30 degrees. To exclude anticoagulation bias, similar analysis was also performed in the cohort of non-anticoagulated patients.

Results

117 patients were included; the prevalence of LT was 13.7% [13/93 cases (14.0%) of Lotus valves and 3/24 cases (12.5%) of Sapien 3 valves]. Baseline demographics (age, STS score, cardiac risk factors) and procedural characteristics (access site, post-dilation, repositioning) were similar in both groups. None of the patients with LT were discharged on anticoagulation therapy (0.0% vs 22.8%, p&lt;0.01). There were no differences in actual prosthesis area, perimeter or eccentricity at the three prosthesis levels. Patients with LT had reduced annulus expansion (89.3±9.8% vs 94.6±8.3%, p=0.02), lower implant depth (6.9±1.5mm vs 4.9±1.5mm, p&lt;0.01) and more significant CMA (81.3% vs 48.5%, p=0.02). These findings were similar in patients that were not anticoagulated (94/117 patients).

Conclusion

Patients with LT had reduced annulus expansion, lower implant depth and greater CMA. These findings were not affected by presence or absence of anticoagulation. These factors may be important considerations during procedural planning for TAVR.

Graphical abstract

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council (NHMRC). National Heart Foundation (NHF) Australia.

Prognostic factors influencing survival in patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for isolated colorectal peritoneal metastases: a systematic review and meta-analysis

AIM

Peritoneal metastases from colorectal cancer confer the worst survival among all metastatic sites. The adoption of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer selected patients with isolated colorectal peritoneal metastases (CRPM) a favourable long-term survival. There are numerous factors postulated to influence survival in patients undergoing CRS and HIPEC. The aim of this study was to identify the key perioperative prognostic factors that influence survival in patients undergoing CRS and HIPEC for isolated CRPM.

METHOD

A systematic review and meta-analysis were conducted to evaluate prognostic factors influencing survival in patients undergoing CRS and HIPEC for isolated CRPM.

RESULTS

Thirty-three studies fitted the inclusion criteria for the systematic review, with 25 studies included in the meta-analysis. On pooled analysis, incomplete cytoreduction, increasing peritoneal carcinoma index (PCI) and lymph node involvement were significantly associated with a worse survival. Additionally, a rectal primary [hazard ratio (HR) 1.93, 95% CI 1.10-3.37], adjuvant chemotherapy (HR 0.71, 95% CI 0.54-0.93) and perioperative grade III/IV morbidity (HR 1.59, 95% CI 1.17-2.16) were also found to significantly influence survival. Notably, tumour differentiation and signet ring cell histology did not influence survival on pooled analysis.

CONCLUSION

This meta-analysis confirms that in patients undergoing CRS and HIPEC for isolated CRPM, incomplete cytoreduction, high PCI and lymph node involvement have a negative influence on survival. In addition, a rectal primary, adjuvant chemotherapy use and grade III/IV morbidity are important factors that also significantly influence survival.

Lithological constraints on resource economies shape the mycorrhizal composition of a Bornean rain forest

Arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) produce contrasting plant-soil feedbacks, but how these feedbacks are constrained by lithology is poorly understood. We investigated the hypothesis that lithological drivers of soil fertility filter plant resource economic strategies in ways that influence the relative fitness of trees with AMF or EMF symbioses in a Bornean rain forest containing species with both mycorrhizal strategies. Using forest inventory data on 1245 tree species, we found that although AMF-hosting trees had greater relative dominance on all soil types, with declining lithological soil fertility EMF-hosting trees became more dominant. Data on 13 leaf traits and wood density for a total of 150 species showed that variation was almost always associated with soil type, whereas for six leaf traits (structural properties; carbon, nitrogen, phosphorus ratios, nitrogen isotopes), variation was also associated with mycorrhizal strategy. EMF-hosting species had slower leaf economics than AMF-hosts, demonstrating the central role of mycorrhizal symbiosis in plant resource economies. At the global scale, climate has been shown to shape forest mycorrhizal composition, but here we show that in communities it depends on soil lithology, suggesting scale-dependent abiotic factors influence feedbacks underlying the relative fitness of different mycorrhizal strategies.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.