A Randomised Phase II Trial to Evaluate the Feasibility of Radiotherapy Dose Escalation, Facilitated by Intensity-Modulated Arc Radiotherapy Techniques, in High-Risk Neuroblastoma

BACKGROUND AND PURPOSE

For high-risk neuroblastoma, planning target volume coverage is often compromised to respect adjacent kidney tolerance. This trial investigated whether intensity-modulated arc radiotherapy techniques (IMAT) could facilitate dose escalation better than conventional techniques.

MATERIALS AND METHODS

Children with high-risk abdominal neuroblastoma referred for radiotherapy to the primary tumour site and involved regional lymph nodes were randomised to receive either standard dose (21 Gy in 14 fractions) or escalated dose (36 Gy in 24 fractions) radiotherapy. Dual planning with both a conventional anterior-posterior parallel opposed pair radiotherapy technique and an IMAT technique was performed. The quality of target volume and organ-at-risk delineation, and dosimetric plans, were externally reviewed. Dosimetric parameters were used to judge the superior technique for treatment. This feasibility trial was not powered to detect improvement in outcome with dose escalation.

RESULTS

Between 2017 and 2020, 50 patients were randomised and dual-planned. The IMAT technique was judged more favourable in 48 patients. In all patients randomised to receive 36 Gy, IMAT would have permitted delivery of the full dose (median D50% 36.0 Gy, inter-quartile range 36.0-36.1 Gy) to the target volume, whereas dose compromise would have been required with conventional planning (median D50% 35.6 Gy, inter-quartile range 28.7-35.9 Gy).

CONCLUSION

IMAT facilitates safe dose escalation to 36 Gy in patients receiving radiotherapy for neuroblastoma. The value of dose escalation is now being evaluated in a current prospective phase III randomised trial.

Fully Automated Measurement of the Insall-Salvati Ratio with Artificial Intelligence

Patella alta (PA) and patella baja (PB) affect 1-2% of the world population, but are often underreported, leading to potential complications like osteoarthritis. The Insall-Salvati ratio (ISR) is commonly used to diagnose patellar height abnormalities. Artificial intelligence (AI) keypoint models show promising accuracy in measuring and detecting these abnormalities.An AI keypoint model is developed and validated to study the Insall-Salvati ratio on a random population sample of lateral knee radiographs. A keypoint model was trained and internally validated with 689 lateral knee radiographs from five sites in a multi-hospital urban healthcare system after IRB approval. A total of 116 lateral knee radiographs from a sixth site were used for external validation. Distance error (mm), Pearson correlation, and Bland-Altman plots were used to evaluate model performance. On a random sample of 2647 different lateral knee radiographs, mean and standard deviation were used to calculate the normal distribution of ISR. A keypoint detection model had mean distance error of 2.57 ± 2.44 mm on internal validation data and 2.73 ± 2.86 mm on external validation data. Pearson correlation between labeled and predicted Insall-Salvati ratios was 0.82 [95% CI 0.76-0.86] on internal validation and 0.75 [0.66-0.82] on external validation. For the population sample of 2647 patients, there was mean ISR of 1.11 ± 0.21. Patellar height abnormalities were underreported in radiology reports from the population sample. AI keypoint models consistently measure ISR on knee radiographs. Future models can enable radiologists to study musculoskeletal measurements on larger population samples and enhance our understanding of normal and abnormal ranges.

Pathogenic Roles for RNASET2 in Clear Cell Renal Cell Carcinoma

A specific splicing isoform of RNASET2 is associated with worse oncologic outcomes in clear cell renal cell carcinoma (ccRCC). However, the interplay between wild-type RNASET2 and its splice variant and how this might contribute to the pathogenesis of ccRCC remains poorly understood. We sought to better understand the relationship of RNASET2 in the pathogenesis of ccRCC and the interplay with a pathogenic splicing isoform (RNASET2-SV) and the tumor immune microenvironment. Using data from The Cancer Genome Atlas and Clinical Proteomic Tumor Analysis Consortium, we correlated clinical variables to RNASET2 expression and the presence of a specific RNASET2-SV. Immunohistochemical staining with matched RNA sequencing of ccRCC patients was then utilized to understand the spatial relationships of RNASET2 with immune cells. Finally, in vitro studies were performed to demonstrate the oncogenic role of RNASET2 and highlight its potential mechanisms. RNASET2 gene expression is associated with higher grade tumors and worse overall survival in The Cancer Genome Atlas cohort. The presence of the RNASET2-SV was associated with increased expression of the wild-type RNASET2 protein and epigenetic modifications of the gene. Immunohistochemical staining revealed increased intracellular accumulation of RNASET2 in patients with increased RNA expression of RNASET2-SV. In vitro experiments reveal that this accumulation results in increased cell proliferation, potentially from altered metabolic pathways. RNASET2 exhibits a tumor-promoting role in the pathogenesis of ccRCC that is increased in the presence of a specific RNASET2-SV and associated with changes in the cellular localization of the protein.

Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning

PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (-26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water-insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.

Use of Suprapubic Panniculus for Split-Thickness Skin Graft in Buried Penis Repair

Background

In the United States, acquired buried penis deformity is an increasingly more common condition. Management of the buried penis deformity is accomplished with removal of macerated skin and subcutaneous tissue from the panniculus and prepubic region, and replacement of denuded penile skin. If local tissue advancement is insufficient to cover the defect, a skin graft may be required. Though the anterior thigh is commonly used, this creates a second defect. Here we describe 2 cases of split-thickness skin grafts harvested from the panniculus to cover buried penis deformities.

Methods

Two patients with a buried penis deformity were identified. The denuded suprapubic tissue was elevated. Using inferior traction, split-thickness skin grafts were harvested and placed onto the shaft of the penis. The remaining excess tissue was resected.

Results

One patient had a fungal rash that resolved with topical treatment. The other patient had a hematoma requiring surgical evacuation. Neither patient had any other complications, and both had over 95% take of the split-thickness skin grafts.

Conclusions

These cases demonstrate the successful use of pannicular skin grafts for buried penis deformity correction. This donor site avoids creation of a second defect. As demonstrated here, the grafts are a durable option, even in the setting of local infection and hematoma.

Novel Ameloblastin Variants, Contrasting Amelogenesis Imperfecta Phenotypes

Amelogenesis imperfecta (AI) comprises a group of rare, inherited disorders with abnormal enamel formation. Ameloblastin (AMBN), the second most abundant enamel matrix protein (EMP), plays a critical role in amelogenesis. Pathogenic biallelic loss-of-function AMBN variants are known to cause recessive hypoplastic AI. A report of a family with dominant hypoplastic AI attributed to AMBN missense change p.Pro357Ser, together with data from animal models, suggests that the consequences of AMBN variants in human AI remain incompletely characterized. Here we describe 5 new pathogenic AMBN variants in 11 individuals with AI. These fall within 3 groups by phenotype. Group 1, consisting of 6 families biallelic for combinations of 4 different variants, have yellow hypoplastic AI with poor-quality enamel, consistent with previous reports. Group 2, with 2 families, appears monoallelic for a variant shared with group 1 and has hypomaturation AI of near-normal enamel volume with pitting. Group 3 includes 3 families, all monoallelic for a fifth variant, which are affected by white hypoplastic AI with a thin intact enamel layer. Three variants, c.209C>G; p.(Ser70*) (groups 1 and 2), c.295T>C; p.(Tyr99His) (group 1), and c.76G>A; p.(Ala26Thr) (group 3) were identified in multiple families. Long-read AMBN locus sequencing revealed these variants are on the same conserved haplotype, implying they originate from a common ancestor. Data presented therefore provide further support for possible dominant as well as recessive inheritance for AMBN-related AI and for multiple contrasting phenotypes. In conclusion, our findings suggest pathogenic AMBN variants have a more complex impact on human AI than previously reported.

Hepatic Ischemia-reperfusion Injury: Protective Approaches and Treatment

Ischemia and reperfusion damage to the liver is one of the major causes of hepatic dysfunction and liver failure after a liver transplant. The start of hepatic ischemia-reperfusion damage is linked to metabolic acidosis, Kupffer cells, neutrophils, excessive calcium, and changes in the permeability of the mitochondrial membrane. Hypoxia activates Kupffer cells, resulting in the production of reactive oxygen species (ROS). These ROS when accumulated, causes apoptosis and necrosis, as well as activate immune and inflammatory responses that involve many cells and signalling molecules. Numerous antioxidant compounds have been researched to lessen oxidative stress and thus serve as potential compounds to deal the ischemia-reperfusion damage. This article confers a deep understanding of the protective effects of some effective therapies, including hepatoprotective agents, attenuation of an increase in xanthine oxidase activity, and administration of antioxidants like N-acetylcysteine, superoxide dismutase (SOD), and ornithine.

A Spatially Resolved and Environmentally Informed Forecast Model of West Nile Virus in Coachella Valley, California

West Nile virus (WNV) is the most significant arbovirus in the United States in terms of both morbidity and mortality. West Nile exists in a complex transmission cycle between avian hosts and the arthropod vector, Culex spp. mosquitoes. Human spillover events occur when humans are bitten by an infected mosquito and predicting these rates of infection and therefore the risk to humans may be associated with fluctuations in environmental conditions. In this study, we evaluate the hydrological and meteorological drivers associated with mosquito biology and viral development to determine if these associations can be used to forecast seasonal mosquito infection rates with WNV in the Coachella Valley of California. We developed and tested a spatially resolved ensemble forecast model of the WNV mosquito infection rate in the Coachella Valley using 17 years of mosquito surveillance data and North American Land Data Assimilation System-2 environmental data. Our multi-model inference system indicated that the combination of a cooler and dryer winter, followed by a wetter and warmer spring, and a cooler than normal summer was most predictive of the prevalence of West Nile positive mosquitoes in the Coachella Valley. The ability to make accurate early season predictions of West Nile risk has the potential to allow local abatement districts and public health entities to implement early season interventions such as targeted adulticiding and public health messaging before human transmission occurs. Such early and targeted interventions could better mitigate the risk of WNV to humans.

Molecular wrench activity of DNA helicases: Keys to modulation of rapid kinetics in DNA repair

DNA helicase activity is essential for the vital DNA metabolic processes of recombination, replication, transcription, translation, and repair. Recently, an unexpected, rapid exponential ATP-stimulated DNA unwinding rate was observed from an Archaeoglobus fulgidus helicase (AfXPB) as compared to the slower conventional helicases from Sulfolobus tokodaii, StXPB1 and StXPB2. This unusual rapid activity suggests a "molecular wrench" mechanism arising from the torque applied by AfXPB on the duplex structure in transitioning from open to closed conformations. However, much remains to be understood. Here, we investigate the concentration dependence of DNA helicase binding and ATP-stimulated kinetics of StXPB2 and AfXPB, as well as their binding and activity in Bax1 complexes, via an electrochemical assay with redox-active DNA monolayers. StXPB2 ATP-stimulated activity is concentration-independent from 8 to 200 nM. Unexpectedly, AfXPB activity is concentration-dependent in this range, with exponential rate constants varying from seconds at concentrations greater than 20 nM to thousands of seconds at lower concentrations. At 20 nM, rapid exponential signal decay ensues, linearly reverses, and resumes with a slower exponential decay. This change in AfXPB activity as a function of its concentration is rationalized as the crossover between the fast molecular wrench and slower conventional helicase modes. AfXPB-Bax1 inhibits rapid activity, whereas the StXPB2-Bax1 complex induces rapid kinetics at higher concentrations. This activity is rationalized with the crystal structures of these complexes. These findings illuminate the different physical models governing molecular wrench activity for improved biological insight into a key factor in DNA repair.

HyenaDNA: Long-Range Genomic Sequence Modeling at Single Nucleotide Resolution

Genomic (DNA) sequences encode an enormous amount of information for gene regulation and protein synthesis. Similar to natural language models, researchers have proposed foundation models in genomics to learn generalizable features from unlabeled genome data that can then be fine-tuned for downstream tasks such as identifying regulatory elements. Due to the quadratic scaling of attention, previous Transformer-based genomic models have used 512 to 4k tokens as context (<0.001% of the human genome), significantly limiting the modeling of long-range interactions in DNA. In addition, these methods rely on tokenizers or fixed k-mers to aggregate meaningful DNA units, losing single nucleotide resolution where subtle genetic variations can completely alter protein function via single nucleotide polymorphisms (SNPs). Recently, Hyena, a large language model based on implicit convolutions was shown to match attention in quality while allowing longer context lengths and lower time complexity. Leveraging Hyena's new long-range capabilities, we present HyenaDNA, a genomic foundation model pretrained on the human reference genome with context lengths of up to 1 million tokens at the single nucleotide-level - an up to 500x increase over previous dense attention-based models. HyenaDNA scales sub-quadratically in sequence length (training up to 160x faster than Transformer), uses single nucleotide tokens, and has full global context at each layer. We explore what longer context enables - including the first use of in-context learning in genomics. On fine-tuned benchmarks from the Nucleotide Transformer, HyenaDNA reaches state-of-the-art (SotA) on 12 of 18 datasets using a model with orders of magnitude less parameters and pretraining data. On the GenomicBenchmarks, HyenaDNA surpasses SotA on 7 of 8 datasets on average by +10 accuracy points. Code at https://github.com/HazyResearch/hyena-dna.

Pediatric anterior choroidal artery aneurysm successfully coiled after re-rupture

Pediatric cerebral aneurysms are rare, and pediatric anterior choroidal artery aneurysms are very rarely reported. A 14-month-old male with no personal or family history of connective tissue disorders or Moyamoya disease presented with a right temporal intracerebral hemorrhage with intraventricular extension. CTA was negative for vascular pathology, but digital subtraction angiography revealed an anterior choroidal artery aneurysm that was successfully coiled. This case underscores the importance of performing digital subtraction angiography in children presenting with intracerebral hemorrhage concerning for vascular pathology even if non-invasive vascular imaging is negative.

The impact of electronic pathways and digital systems on neck of femur fracture outcomes globally: a systematic review

INTRODUCTION

Electronic pathways (e-pathways) and digital systems are novel interventions with several uses in healthcare, ranging from clinical decision support systems to checklists for care delivery. Their application in the management of neck of femur (NOF) fractures is evolving and they may play a key role in facilitating improvements in care delivery. The primary aim of this review was to outline the impact of e-pathways/digital systems on NOF fracture outcomes.

METHODS

A systematic literature search was performed using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. A total of 698 citations were evaluated, of which 38 passed the inclusion/exclusion criteria. Six studies were then finalised following full-text review. Heterogenous data meant a narrative synthesis was undertaken. Risk of bias for each paper was assessed using the Downs and Black scale.

RESULTS

A statistically significant improvement was demonstrated for time to theatre (3/6 studies), length of hospital stay (2/6 studies) and secondary fracture prevention (2/6 studies). Although postoperative delirium and mortality improved with the introduction of e-pathways/digital systems, statistical significance was not achieved. No outcome measures were adversely affected.

CONCLUSIONS

This systematic review of the literature demonstrates that e-pathways and digital systems are promising novel interventions, displaying a significant positive impact on several NOF fracture outcomes. Owing to the novel nature of e-pathways and digital systems in orthopaedics, a limited number of studies were identified for review, each with variable study design. More high quality homogenous prospective cohort studies with a standardised primary outcome measure are required for more definitive conclusions of efficacy to be drawn.

CT vs. MRI: Which is More Accurate in Grading Rectal Wall Infiltration after Hydrogel Spacer Placement for Prostate Cancer Patients?

PURPOSE/OBJECTIVE(S)

The purpose of this study was to evaluate the incidence and severity of rectal wall infiltration (RWI) in prostate cancer patients after rectal hydrogel spacer implantation, a commonly used procedure to minimize rectal radiation exposure during prostate radiotherapy. The study aimed to determine correlation of RWI using computed tomography (CT) scans and magnetic resonance imaging (MRI) scans in order to determine the optimal post-placement imaging modality.

MATERIALS/METHODS

This retrospective study was conducted on 370 patients diagnosed with localized prostate cancer who underwent rectal hydrogel spacer placement from 2020 to 2022. CT scans were performed on all patients, with a smaller subset also undergoing MRI scans. The images were independently evaluated by three radiation oncologists to grade RWI levels using a standardized scoring system based on CT and MRI images after hydrogel placement. The levels were categorized as 0 (no RWI), 1 (focal RWI), 2 (moderate RWI), and 3 (significant RWI).

RESULTS

Any grade of RWI was identified in 79.8% of men with the majority (41%) being RWI grade 1. The median time for CT scans was 9 days after hydrogel spacer placement and 14.5 days for MRI scans. For the subset of patients with both CT and MRI scans after spacer (mostly SpaceOAR Vue), RWI was detected in 58.33% of patients based on CT and 61.11% of patients based on MRI. Table 1 shows the mean percentage of patients with each score of RWI for each imaging modality. MRI was more likely to lead to a designation of RWI of any grade compared to CT and more often led to detection of RWI grades 2-3.

CONCLUSION

Our findings demonstrate that the incidence and severity of RWI may be higher than previously reported in clinical trials and that MRI may be a more sensitive imaging modality. Caution is needed in the utilization of rectal spacer gels given the potential for complications with misplacement prior to radiation therapy. Further study is warranted to determine the potential impact of low-grade RWI on the safety of subsequent treatment.

Multitissue H3K27ac profiling of GTEx samples links epigenomic variation to disease

Genetic variants associated with complex traits are primarily noncoding, and their effects on gene-regulatory activity remain largely uncharacterized. To address this, we profile epigenomic variation of histone mark H3K27ac across 387 brain, heart, muscle and lung samples from Genotype-Tissue Expression (GTEx). We annotate 282 k active regulatory elements (AREs) with tissue-specific activity patterns. We identify 2,436 sex-biased AREs and 5,397 genetically influenced AREs associated with 130 k genetic variants (haQTLs) across tissues. We integrate genetic and epigenomic variation to provide mechanistic insights for disease-associated loci from 55 genome-wide association studies (GWAS), by revealing candidate tissues of action, driver SNPs and impacted AREs. Lastly, we build ARE-gene linking scores based on genetics (gLink scores) and demonstrate their unique ability to prioritize SNP-ARE-gene circuits. Overall, our epigenomic datasets, computational integration and mechanistic predictions provide valuable resources and important insights for understanding the molecular basis of human diseases/traits such as schizophrenia.

Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030

BACKGROUND

We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy.

PATIENTS AND METHODS

We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence.

RESULTS

Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12.

CONCLUSIONS

Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

mTOR-dependent loss of PON1 secretion and antiphospholipid autoantibody production underlie autoimmunity-mediated cirrhosis in transaldolase deficiency

Transaldolase deficiency predisposes to chronic liver disease progressing from cirrhosis to hepatocellular carcinoma (HCC). Transition from cirrhosis to hepatocarcinogenesis depends on mitochondrial oxidative stress, as controlled by cytosolic aldose metabolism through the pentose phosphate pathway (PPP). Progression to HCC is critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Although AR inactivation blocked susceptibility to hepatocarcinogenesis, it enhanced growth restriction, carbon trapping in the non-oxidative branch of the PPP and failed to reverse the depletion of glucose 6-phosphate (G6P) and liver cirrhosis. Here, we show that inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies (aPL), loss of CD161+ NK cells, and expansion of CD38+ Ito cells, which are responsive to treatment with rapamycin in vivo. The present study thus identifies glycosylation and secretion of PON1 and aPL production as mTOR-dependent regulatory checkpoints of autoimmunity underlying liver cirrhosis in TAL deficiency.

Glutaredoxin proteins from E. coli isoforms were compared in terms of energy frustration

Glutaredoxin (GRXs) protein plays a vital role inside the cell, including redox control of transcription to the cell's antioxidant defense, apoptosis, and cellular differentiation regulation. In this study, we have investigated the energy landscape and characterized the pattern of local frustration in different forms and states of the GRX protein ofE. coli.Analysis was done on the conformational alterations, significant changes in the frustration pattern, and different GRXs such as GRX-II, GRX-III, GRX-II-GSH, and GRX-III-GSH complex. We have found the practice of frustration, and structure was quite similar in the same isoform having different states of protein; however, a significant difference was observed between different isoforms. Moreover, oxidation of GRX-I introduced an extra α-helix increasing the destabilizing interactions within the protein. The study of frustrated contacts on oxidized and reduced GRX and with bound and unbound Glutathione indicates its potential application in activating and regulating the behavior of GRXs.

The "pipe-anchor" technique: A method for intra-aneurysmal loop reduction using a partially unsheathed pipeline stent

PURPOSE

Large aneurysms often present a challenge for endovascular navigation, as they may require utilization of "around-the-world" technique for distal access. In this study, we describe the use of a pipeline stent to stabilize the microcatheter allowing gradual unsheathing and straightening of the microcatheter within the aneurysm enabling stent deployment.

METHODS

A pipeline stent is partially deployed distal to the aneurysm, after using intra-aneurysmal loop ("around-the-world") to cross the aneurysm. Partially unsheathed, using its radial force and vessel wall friction to establish an anchoring point, the microcatheter is stabilized and pulled with the stent locked to gradually to allow loop reduction and microsystem straightening, allowing unsheathing as the microsystem is aligned with the inflow and outflow vessel.

RESULTS

Two patients harboring cavernous segment aneurysms (measuring 18 × 12 mm and 21 × 24 mm) were treated by 3.75 × 25 mm and 4.25 × 25 mm pipeline devices, respectively, using this technique, deployed through a Phenom 0.027" microcatheter. Patients did well clinically with no thromboembolic complications, as follow-up imaging demonstrated good wall apposition and appreciable contrast stagnation.

CONCLUSION

Anchoring for loop reduction was previously described using a non-flow diverter stents or balloon requiring additional devices and exchange maneuvers to deploy a pipeline. The "pipe anchor" technique describes the use of a partially deployed flow diverter system as an anchor. This report suggests that pipeline radial force, albeit low, is sufficient. We believe that this method is worthy of consideration in select cases as a first choice and can be valuable tool in the armamentarium of the endovascular neurosurgeon.

Evaluation of the impact of continuous Kangaroo Mother Care (KMC) initiated immediately after birth compared to KMC initiated after stabilization in newborns with birth weight 1.0 to < 1.8 kg on neurodevelopmental outcomes: Protocol for a follow-up study

BACKGROUND

Preterm birth or low birth weight is the single largest cause of death in newborns, however this mortality can be reduced through newborn care interventions, including Kangaroo Mother Care (KMC). Previously, a multi-country randomized controlled trial, coordinated by the World Health Organization (WHO), reported a significant survival advantage with initiation of continuous KMC immediately after birth compared with initiation of continuous KMC a few days after birth when the baby is considered clinically stable. Whether the survival advantage would lead to higher rates of neurodevelopmental morbidities, or the immediate KMC will also have a beneficial effect on cognitive development also, has not been investigated. We therefore propose to test the hypothesis that low-birth-weight infants exposed to immediate KMC will have lower rates of neurodevelopmental impairment in comparison to traditional KMC-treated infants, by prospectively following up infants already enrolled in the immediate KMC trial for the first 2 years of life, and assessing their growth and neurodevelopment.

METHODS

This prospective cohort study will enroll surviving neonates from the main WHO immediate KMC trial. The main trial as well as this follow-up study are being conducted in five low- and middle-income countries in South Asia and sub-Saharan Africa. The estimated sample size for comparison of the risk of neurodevelopmental impairment is a total of 2200 children. The primary outcome will include rates of cerebral palsy, hearing impairment, vision impairment, mental and motor development, and epilepsy and will be assessed by the age of 3 years. The analysis will be by intention to treat.

DISCUSSION

Immediate KMC can potentially reduce low-birth-weight-associated complications such as respiratory disease, hypothermia, hypoglycemia, and infection that can result in impaired neurocognitive development. Neuroprotection may also be mediated by improved physiological stabilization that may lead to better maturation of neural pathways, reduced risk of hypoxia, positive parental impact, improved sleep cycles, and improved stress responses. The present study will help in evaluating the overall impact of KMC by investigating the long-term effect on neurodevelopmental impairment in the survivors.

TRIAL REGISTRATION

Clinical Trials Registry-India CTRI/2019/11/021899. Registered on 06 November 2019. Trials registration of parent trial: ACTRN12618001880235; Clinical Trials Registry-India: CTRI/2018/08/015369.

Closed-loop optogenetic control of the dynamics of neural activity in non-human primates

Electrical neurostimulation is effective in the treatment of neurological disorders, but associated recording artefacts generally limit its applications to open-loop stimuli. Real-time and continuous closed-loop control of brain activity can, however, be achieved by pairing concurrent electrical recordings and optogenetics. Here we show that closed-loop optogenetic stimulation with excitatory opsins enables the precise manipulation of neural dynamics in brain slices from transgenic mice and in anaesthetized non-human primates. The approach generates oscillations in quiescent tissue, enhances or suppresses endogenous patterns in active tissue and modulates seizure-like bursts elicited by the convulsant 4-aminopyridine. A nonlinear model of the phase-dependent effects of optical stimulation reproduced the modulation of cycles of local-field potentials associated with seizure oscillations, as evidenced by the systematic changes in the variability and entropy of the phase-space trajectories of seizures, which correlated with changes in their duration and intensity. We also show that closed-loop optogenetic neurostimulation could be delivered using intracortical optrodes incorporating light-emitting diodes. Closed-loop optogenetic approaches may be translatable to therapeutic applications in humans.

Characterization of paddy-residue burning derived carbonaceous aerosols using dual carbon isotopes

A large scale paddy-residue burning (PRB) happens every year in the northwest Indo-Gangetic Plain (IGP) during the post-monsoon season, and winds transport pollutants from the source region up to the northern Indian Ocean affecting air quality of the IGP and marine region. In this study, day-night pairs of fine aerosol samples (n = 69) were collected during October-November over Patiala (30.2°N, 76.3°E, 250 m amsl), a site located in the source region of PRB. Carbonaceous aerosols (CA) were characterised using chemical species and dual carbon isotopes (¹³C and ¹⁴C) to estimate bio vs non-bio contributions and understand their characteristics. Percentage of bio fraction (f_bio, estimated using ¹⁴C) in CA varied from 74 % to 87 % (avg: 80 ± 3) during days and 71 % to 96 % (avg: 85 ± 7 %) during nights. Further, the f_bio was found to be better correlated with aerosol mass spectrometer derived f60 compare to levoglucosan (LG) or nssK⁺, suggesting f60 a useful proxy for PRB. The δ¹³C varied from -27.7 ‰ to -26.0 ‰ (avg: -27.0 ± 0.4 ‰) and - 28.7 ‰ to -26.4 ‰ (avg: -27.5 ± 0.7 ‰) during day and night, respectively. Measured δ¹³C of the samples was found to be more enriched than expected by 0.3 to 2.0 ‰, indicating the presence of aged CA also in Patiala even during PRB period. From f_bio versus δ¹³C correlation, and from Miller-Trans plot, δ¹³C of PRB is found to be -28.9 ± 1.1 ‰, which also infers that Miller-Trans plot can be used to understand source isotopic signature in the absence of radiocarbon measurements in aerosols. Further, the characteristics ratios of organic carbon (OC) to elemental carbon (EC) (11.9 ± 4.1), LG to potassium (K⁺) (0.84 ± 0.15), OC/LG (19.7 ± 2.0) and K⁺/EC (0.75 ± 0.27) were calculated by considering samples with f_bio higher than 0.90, which can be used for source apportionment studies. Such studies are crucial in assessing the effects of PRB on regional air quality and climate.

A213 UNDERSTANDING PATIENT AND PHYSICIAN ATTITUDES AND EXPECTATIONS REGARDING IDENTIFYING AND MANAGING ANXIETY AND DEPRESSION IN IBD

Background

Patients living with Inflammatory Bowel Disease (IBD) commonly experience a number of mental health-related challenges, specifically anxiety and mood disorders (AMDs). Although there has been an awareness of the relationship between IBD and AMD within the GI research and clinical space; detection, treatment, and management amongst care providers is limited. Therefore, we are seeking to explore the overall experiences of patients living with Inflammatory Bowel Disease to identify and evaluate their experiences in interactions with GI clinicians around mental health in diverse care settings in order to determine how to best support mental health care amongst IBD patients.

Purpose

We aimed to explore perspectives, experiences and barriers to engaging with mental health-related challenges amongst IBD patients when interacting with gastroenterologists over the course of their health journey.

Method

We conducted 5 semi-structured online focus groups co-facilitated by patient researchers in early 2020 through Zoom which spanned for a total of 2.5 hours each. Participants were recruited through social media channels, GI clinics, the IMAGINE-SPOR unit, and Crohn’s and Colitis Canada. A semi-structured interview guide was developed for patient researchers to follow during the focus groups which provided guided questions that would allow patient participants to explore and reflect on: their experiences living with IBD, their expectations around mental health support, their perception of the engagement of GIs in mental health discussions, and their expectations for mental health support and services moving forward. Audio recordings from the semi-structured focus groups were then transcribed and thematic analysis was used to identify emerging themes and patient expectations.

Result(s)

We identified the following key themes: 1) experiences with IBD: difficulties related to reintegrating into social settings, feelings of loneliness; 2) expectations around mental health support: the need to develop their own resiliency strategies due to the lack of structural resources regarding mental health and IBD in the clinical space; 3) GI engagement: HCPs were dismissive of mental health symptoms, often gaslighting patients when mentioning mental health concerns during clinical encounters; and 4) expectations: a need to standardize mental health care across IBD care practice with a focus on potentially integrating healthcare providers of diverse care settings to help address the need for mental health support in such a vast patient population.

Conclusion(s)

Our study suggests that effective detection, management and awareness, along with the integration of feedback from patient lived experiences can help inform the development of mental health support and services which cater to the needs of people living with IBD. Results from this study will be interpreted in line with insight gathered from upcoming interviews of gastroenterologists and HCPs.

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CIHR, Other

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IMAGINE SPOR INCUBATOR Grant

Disclosure of Interest

None Declared

Fournier's gangrene reconstruction: A 10-year retrospective analysis of practice at Guys and St Thomas's NHS Foundation Trust

Fournier's gangrene is a rare and potentially fatal condition that affects the external genitalia and perineum as a necrotizing soft-tissue infection. It is equally prevalent in men and women and although there are many ways to manage the condition, it must be done so effectively because there is a chance that life-threatening complications could develop. This retrospective study set out to fill any knowledge gaps, compare reconstructive options to those described in the literature, and promote reflection on current management. Between January 2010 and January 2020, all perineal debridement operation notes were examined. The primary conclusions were that a large majority of defects could be repaired using split skin grafts to reduce surgical time and donor site morbidity. To avoid secondary contracture and the need for revision surgery, full-thickness skin grafts should be used whenever possible to treat penile defects.

Covered stent delivery in tortuous internal carotid artery for treatment of direct carotid cavernous fistula

Direct carotid cavernous fistulas (dCCF) are high-flow shunts between the internal carotid artery (ICA) and cavernous sinus and are commonly caused by traumatic injuries. Endovascular intervention using detachable coils, with or without stenting, is often the treatment of choice; however, migration or compaction of the coils can occur due to high-flow nature of dCCFs. Alternatively, deployment of a covered stent in ICA can be considered for treatment of dCCFs. We report a case of dCCF with tortuous intracranial ICA successfully treated by placement of a covered stent graft and we will illustrate the technical aspects of the procedure. In the presence of a tortuous ICA navigation and deployment of covered stents is technically complicated and requires modified maneuvers.

Development and validation of a risk score (Delay-7) to predict the occurrence of a treatment delay following cycle 1 chemotherapy

BACKGROUND

The risk of toxicity-related dose delays, with cancer treatment, should be included as part of pretreatment education and be considered by clinicians upon prescribing chemotherapy. An objective measure of individual risk could influence clinical decisions, such as escalation of standard supportive care and stratification of some patients, to receive proactive toxicity monitoring.

PATIENTS AND METHODS

We developed a logistic regression prediction model (Delay-7) to assess the overall risk of a chemotherapy dose delay of 7 days for patients receiving first-line treatments for breast, colorectal and diffuse large B-cell lymphoma. Delay-7 included hospital treated, age at the start of chemotherapy, gender, ethnicity, body mass index, cancer diagnosis, chemotherapy regimen, colony stimulating factor use, first cycle dose modifications and baseline blood values. Baseline blood values included neutrophils, platelets, haemoglobin, creatinine and bilirubin. Shrinkage was used to adjust for overoptimism of predictor effects. For internal validation (of the full models in the development data) we computed the ability of the models to discriminate between those with and without poor outcomes (c-statistic), and the agreement between predicted and observed risk (calibration slope). Net benefit was used to understand the risk thresholds where the model would perform better than the 'treat all' or 'treat none' strategies.

RESULTS

A total of 4604 patients were included in our study of whom 628 (13.6%) incurred a 7-day delay to the second cycle of chemotherapy. Delay-7 showed good discrimination and calibration, with c-statistic of 0.68 (95% confidence interval 0.66-0.7), following internal validation and calibration-in-the-large of -0.006.

CONCLUSIONS

Delay-7 predicts a patient's individualised risk of a treatment-related delay at cycle two of treatment. The score can be used to stratify interventions to reduce the occurrence of treatment-related toxicity.

1362 ANTICHOLINERGIC PRESCRIBING HABITS AND ITS ASSOCIATIONS IN A COMMUNITY POPULATION OF PEOPLE LIVING WITH DEMENTIA

Introduction

Many commonly prescribed medications have inadvertent anticholinergic effects. People with Dementia (PwD) are more vulnerable to these effects and at risk of adverse outcomes, the risk being higher with a greater degree of anticholinergic exposure. We investigated prescribing patterns and Anticholinergic burden (ACB) in a cohort of community-dwelling older adults with dementia and aimed to explore the effect of ACB on cognition, mood, and quality of life(QoL).

Method

The medication and demographic information for 87 (39 female) community-dwelling PwD were obtained from Electronic Care Summaries. We used the German Anticholinergic Burden Scale (GABS) to measure ACB. Additionally, we investigated associations between ACB and cognitive (ADAS-Cog), functional (BADL) and QoL (DemQoL) assessments.

Results

28.7% of participants had a clinically significant score (ACB&gt; 2). The most commonly prescribed medications with ACB were Lansoprazole(18.3%), Mirtazapine(12.6%) and Codeine(12.6%). ACB was higher in males and negatively correlated with age, r(87)=-.21,p=.03. There was no association between ACB and cognition, QoL, functional independence, and neuropsychiatric symptoms. Over six months, PLWD with no ACB had a greater negative change in neuropsychiatric symptoms[t(18)=2.27,p=.04] and functional independence[t(23)=-3.8,p=.001], indicating greater dependence and worsening neuropsychiatric symptoms.

Conclusion

A third of PLWD in the community had clinically significant ACB. No ACB was associated with worsening neuropsychiatric symptoms and functional dependence over a six-month period. Community prescribers should consider regular medication reviews with PLWD and carers to ensure medications are prescribed safely and appropriately.

Enhanced photoluminescence of potassium-doped tungsten oxide by acetone exposure

Studies of optical properties of doped nanocrystals of tungsten trioxide can elucidate new information about the material. A novel molecule-enhanced photoluminescence (PL) of potassium-doped tungsten trioxide (K _x WO) was explored in the presence of different gases to understand charge transfer between molecules and K _x WO on the properties of the material. We performed Raman spectroscopy and PL experiments in the presence of gaseous acetone or ethanol mixed with other gases (N₂ and O₂). PL at 630 nm from K _x WO was observed and further enhanced when the sample was continuously irradiated with a 532 nm CW laser in acetone. A mechanism of strong emission of the PL induced by the charge transfer between the acetone and the K _x WO is proposed.

Validating low-fidelity arthroscopic simulation in medical students: a feasibility trial

INTRODUCTION

With surgical opportunities becoming increasingly restricted for orthopaedic trainees, simulation training is a valuable alternative at providing sufficient practice. This pilot study aims to assess the potential effectiveness of low-fidelity simulation in teaching medical students basic arthroscopic skills and the feasibility of its incorporation into formal student training programmes.

METHODS

Twenty-two medical students completed pre- and post-training tests on the Probing (Task 1) and Maze (Task 2) exercises from the Sawbones 'Fundamentals of Arthroscopy Surgery Training' (FAST) programme. Training consisted of practising horizon control, deliberate linear motion and probing within 25min over a period of days. Completion time and error frequency were measured. The difference in performance was assessed using a paired two-tailed t-test. Qualitative data were collected.

RESULTS

Test completion time decreased significantly by a mean of 83s (±46s, 95% confidence intervals [CI] 37 to 129) for Task 1 (p=0.001) and 105s (±55s, 95% CI 50 to 160) for Task 2 (p=0.0007). Frequency of direct visualisation errors decreased significantly by a mean of 1.0 errors (±1.0 errors, 95% CI 0.1 to 2.0) for Task 1 (p = 0.04) and 0.8 errors (±0.8 errors, 95% CI 0.1 to 1.6) for Task 2 (p = 0.04). At post-training, 82% of participants were willing to incorporate FAST into formal training.

CONCLUSIONS

Low-fidelity simulators such as FAST can potentially teach basic arthroscopic skills to medical students and are feasible for incorporation into formal training. They also give students a cost-effective and safe basic surgical training experience.

Metal nanoparticles produced by plants with antibacterial properties against Staphylococcus aureus

Staphylococcus aureus (S. aureus) is a pathogenic bacteria that causes a variety of potentially fatal infections. The emergence of antibiotic-resistant strains of S. aureus has made treatment even more difficult. In recent years, nanoparticles have been used as an alternative therapeutic agent for S. aureus infections. Among various methods for the synthesis of nanoparticles, the method utilizing plant extracts from different parts of a plant, such as root, stem, leaf, flower, seeds, etc. is gaining widespread usage. Phytochemicals present in plant extract are an inexpensive, eco-friendly, natural material that act as reducing and stabilization agent for the nanoparticle synthesis. The utilization of plant-fabricated nanoparticles against S. aureus is currently in trend. The current review discusses recent findings in the therapeutic application of phytofabricated metal-based nanoparticles against Staphylococcus aureus.

Cytosolic aldose metabolism contributes to progression from cirrhosis to hepatocarcinogenesis

Oxidative stress modulates carcinogenesis in the liver; however, direct evidence for metabolic control of oxidative stress during pathogenesis, particularly, of progression from cirrhosis to hepatocellular carcinoma (HCC), has been lacking. Deficiency of transaldolase (TAL), a rate-limiting enzyme of the non-oxidative branch of the pentose phosphate pathway (PPP), restricts growth and predisposes to cirrhosis and HCC in mice and humans. Here, we show that mitochondrial oxidative stress and progression from cirrhosis to HCC and acetaminophen-induced liver necrosis are critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Both TAL and AR are confined to the cytosol; however, their inactivation distorts mitochondrial redox homeostasis in opposite directions. The results suggest that AR acts as a rheostat of carbon recycling and NADPH output of the PPP with broad implications for disease progression from cirrhosis to HCC.

Utility of sirolimus coated balloons in the peripheral vasculature – a review of the current literature

Sirolimus-coated balloons (SCB) have demonstrated much promise as an alternative drug eluting device to the existing paclitaxel coated balloon platforms for the treatment of peripheral arterial disease (PAD). They have been well tested pre-clinically and have demonstrated anti-restenotic effects as well as clinical safety in its use for treatment of coronary artery disease. The existing approved SCBs have thus far demonstrated good short-term patency (12-months) and did not exhibit any major adverse events or device related shortcomings in its use for treatment of PAD. There are several studies ongoing which aim to further investigate the efficacy of existing SCBs and establish a direct comparison of its outcomes compared with plain balloon angioplasty. Also, SCB utility to salvage failing arteriovenous fistulas for haemodialysis patients has also been explored. We review the current progress made in the establishment of SCB in the treatment of PAD as well as highlight ongoing studies investigating the role of SCB in various settings.

High-Flow Nasal Oxygenation and Its Applicability in COVID Patients

High-flow nasal oxygenation (HFNO) is a type of oxygen therapy that provides humidified and heated oxygen through a nasal cannula at much higher flow rates than standard oxygen therapy, while also allowing control over the fraction of inspired oxygen (FIO₂). Compared to standard oxygen therapy, it is much more comfortable for the patient and seems to alleviate most of the problems associated with standard oxygen therapy, such as dry nose, dry throat and nasal pain. It also provides a variety of benefits that can reduce the incidence of escalating treatment and initiating mechanical ventilation in COVID patients with acute hypoxemic respiratory failure (AHRF). This article provides an overview of HFNO and its current applications in COVID patients during the pandemic.

External ventricular drain placement is associated with lower mortality after intracerebral hemorrhage with intraventricular hemorrhage

Background and aims

Many patients with intracerebral hemorrhage (ICH) develop intraventricular hemorrhage (IVH), which is associated with higher mortality and worse clinical outcome. External ventricular drains (EVDs) are often placed, but there is little data on how much patients benefit from this intervention. We explored the use, timing, and location of EVD in ICH patients and any association with clinical outcome.

Results

During the study period, 2870 patients presented with primary ICH, and 2486 were included in analyses. Overall, patients were 73 (± 13) years old; 54% were male, and 46% had associated IVH. An EVD was placed in 29% of patients with IVH and 4% of those without. IVH patients with EVD were younger (67 ± 13 vs 74 ± 13, p < 0.001), had larger IVH volumes (17 mL vs 8 mL, p < 0.001), and lower GCS scores (7 vs 10, p < 0.001), compared to those without EVD. Ninety-day mortality was available in 2486 (100%) patients, while 90-day mRS was available in 1673 (67.3%). In univariate analysis, EVD placement was associated with lower likelihood of 90-day mortality (53% vs 59%, p = 0.048) but higher likelihood of poor outcome (88% vs 85%, p < 0.001) in those for whom this was available. Those with poor outcomes underwent faster EVD placement (0.46 days vs. 0.96 days, p = 0.01). In multivariate analysis, EVD placement was associated with lower 90-day mortality (OR 0.19, 95% CI 0.053–0.657, p = 0.009), but not with lower odds of poor outcome (OR 1.64, 95% CI 0.508–5.309, p = 0.4). In multivariate analysis, days to EVD placement was associated with lower 90-day mortality (OR 0.69, 95% CI 0.49–0.96, p = 0.027).

Conclusion

IVH is relatively common after ICH. After controlling for potential confounds, EVD placement is associated with lower mortality, but not clearly with better neurologic outcome. In addition, more rapid EVD placement is associated with higher mortality, potentially reflecting early development of herniation or obstructive hydrocephalus.