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.

Endoscopic Botulinum toxin as a treatment for delayed gastric emptying following oesophagogastrectomy

INTRODUCTION

The incidence of delayed gastric emptying (DGE) following oesophagogastrectomy with gastric conduit reconstruction is reported to be between 1.7% and 50%. This variation is due to differing practices of intraoperative pylorus drainage procedures, which increase the risk of postoperative biliary reflux and dumping syndrome, resulting in significant morbidity. The aim of our study was to establish rates of DGE in people undergoing oesophagogastrectomy without routine intraoperative drainage procedures, and to evaluate outcomes of postoperative endoscopically administered Botulinum toxin into the pylorus (EBP) for people with DGE resistant to systemic pharmacological treatment.

METHODS

All patients undergoing oesophagogastrectomy between 1 January 2016 and 31 March 2018 at our unit were included. No intraoperative pyloric drainage procedures were performed, and DGE resistant to systemic pharmacotherapy was managed with EBP.

RESULTS

Ninety-seven patients were included. Postoperatively, 29 patients (30%) were diagnosed with DGE resistant to pharmacotherapy. Of these, 16 (16.5%) were diagnosed within 30 days of surgery. The median pre-procedure nasogastric tube aspirate was 780ml; following EBP, this fell to 125ml (p<0.001). Median delay from surgery to EBP in this cohort was 13 days (IQR 7-16 days). Six patients required a second course of EBP, with 100% successful resolution of DGE before discharge. There were no procedural complications.

CONCLUSIONS

This is the largest series of patients without routine intraoperative drainage procedures. Only 30% of patients developed DGE resistant to pharmacotherapy, which was managed safely with EBP in the postoperative period, thus minimising the risk of biliary reflux in people who would otherwise be at risk following prophylactic pylorus drainage procedures.

Structural investigation of borosilicate glasses containing lanthanide ions

High level radioactive actinides are produced as a side product in reprocessing spent nuclear fuel, for which safe long-term-inert immobilizer matrices are needed. Borosilicate glasses are of great potential amongst the candidates of suitable inert materials for radioactive waste immobilization. Understanding the effects of actinide addition to a borosilicate glass matrix is of great importance in view of waste immobilization. Here we present structural studies of a simplified glass-matrix, - 55SiO₂·10B₂O₃·25Na₂O·5BaO·5ZrO₂ - upon adding lanthanide (Ln-)oxides: CeO₂, Nd₂O₃, Eu₂O₃, in two different concentrations 10% and 30w% each, to investigate the effects of lanthanides (Ln) taken as chemical surrogates for actinides. Neutron diffraction combined with of Reverse Monte Carlo simulations show that all investigated glass structures comprise tetrahedral SiO₄, trigonal BO₃ and tetrahedral BO₄ units, forming mixed ^[4]Si-O-^[3]B and ^[4]Si-O-^[4]B linkages. ¹¹B Magic Angle Spinning Nuclear Magnetic Resonance is indicative of simultaneous presence of trigonal BO₃ and tetrahedral BO₄ units, with spectral fractions strongly dependent on the Ln addition. Ln-addition promote the BO₃ + O^-→[BO₄]^- isomerization resulting in lower fraction of boron in BO₃, as compared to BO₄ units. Raman spectra, in full agreement with neutron diffraction, confirm that the basic network structure consists of BO₃/trigonal and SiO₄/BO₄ tetrahedral units. Second neighbour atomic pair correlations reveal Ce, Nd, Eu to be accommodated in both Si and B sites, supporting that the borosilicate-matrix well incorporates Ln-ions and is likely to similarly incorporate actinides, opening a way to radioactive nuclear waste immobilization of this group of elements in a borosilicate glass matrix.

Automated analysis of immunosequencing datasets reveals novel immunoglobulin D genes across diverse species

Immunoglobulin genes are formed through V(D)J recombination, which joins the variable (V), diversity (D), and joining (J) germline genes. Since variations in germline genes have been linked to various diseases, personalized immunogenomics focuses on finding alleles of germline genes across various patients. Although reconstruction of V and J genes is a well-studied problem, the more challenging task of reconstructing D genes remained open until the IgScout algorithm was developed in 2019. In this work, we address limitations of IgScout by developing a probabilistic MINING-D algorithm for D gene reconstruction, apply it to hundreds of immunosequencing datasets from multiple species, and validate the newly inferred D genes by analyzing diverse whole genome sequencing datasets and haplotyping heterozygous V genes.

Antibodies provide specific binding to an enormous range of antigens and represent a key component of the adaptive immune system. Immunosequencing has emerged as a method of choice for generating millions of reads that sample antibody repertoires and provides insights into monitoring immune response to disease and vaccination. Most of the previous immunogenomics studies rely on the reference germline genes in the immunoglobulin locus rather than the germline genes in a specific patient. This approach is deficient since the set of known germline genes is incomplete (particularly for non-European humans and non-human species) and contains alleles that resulted from sequencing and annotation errors. The problem of de novo inference of diversity (D) genes from immunosequencing data remained open until the IgScout algorithm was developed in 2019. We address limitations of IgScout by developing a probabilistic MINING-D algorithm for D gene reconstruction and infer multiple D genes across multiple species that are not present in standard databases.

P5497The gender paradox in non-ST-segment elevation acute coronary syndrome: an outdated paradigm or a persistent reality-an analysis of contemporary practice from an integrate health care system

Introduction

Although sex related differences in Non-ST-Segment elevation (NSTEMI) acute coronary syndrome (ACS) have been well delineated in the past, there is a paucity of data from contemporary practice on the evolutions of this paradox and its clinical practice implications.

Purpose

We hypothesized that in the era of guideline driven contemporary practice, and in the setting of an integrated heath care model, gender related differences in care and outcomes would be marginal at best if no altogether absent.

Methods

We utilized data from an integrated health care system to identify 4099 patients with NSTEMI-ACS (1531 women; 2561 men). The patients were stratified by gender and a comparative analysis was performed on guideline directed medical therapy, revascularization strategy and major adverse cardiac events between the two groups.

Results

There were significant difference in pharmacologic treatment, catheter based interventions and surgical revascularizations strategies. Underutilization of guideline directed medical therapy was demonstrated in women specifically vis a vis angiotensin converting enzyme inhibitor (ACE-I) (p=0.0014), statins (p=0.0001), and antiplatelet therapy: clopodigrel (p=0.0004), prasugrel (p=0.0012), and ticagrelor (p=0.03). Additionally, clear differences emerged in percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) options despite similarities in high risk status at index presentation by well validated risk algorithms. Specifically, men were more likely to undergo PCI (p=0.021) and CABG (p<0.001) than women. Finally, women had a greater incidence of bleeding complications (p=0.0003) and stroke (p=0,038).

Conclusions

There were treatment disparities in pharmacologic interventions, catheter based interventions, surgical revascularization access and clinical outcomes among patients with NSTEMI-ACS. The persistence of this gender paradox in contemporary practice and despite increasing education and awareness should potentiate further public policy initiatves as well as reinforce the need for geneder specific guidelines

Towards accessible nanophotonics: multimode interferometer on strip-loaded slot waveguide

Nano- and micro-photonics are the key-enabling tools for future integrated components and circuitry operating at low power and high speed. By using a strip-loaded platform, we show how we can dramatically reduce the complexity, in terms of fabrication and tolerances, of the most advanced devices. Different configurations of multimode interference devices are presented. We show the design, fabrication, and optical characterization of these components.

Direct and indirect relationships among posttraumatic stress disorder, depression, hostility, anger, and verbal and physical aggression in returning veterans

Hostility, anger, and aggression are conceptually related but unique constructs found to occur more often among veterans with posttraumatic stress disorder (PTSD) than among civilians or veterans without PTSD. However, the pathways between PTSD, depression, hostility, anger, and aggression have not been comprehensively characterized. Therefore, drawing on a sample of returning Operation Enduring Freedom/Operation Iraqi Freedom combat veterans ( N = 175; 95% male; mean age 30 years), this study sought to examine the direct and indirect relationships among PTSD, depression, hostility, anger, and four types of aggression: verbal, and physical toward self, others, and objects. Functional modeling of direct effects was done using multiple least-squares regression and bootstrapped mediation analyses were carried out to test indirect effects. Results indicate that PTSD is not the overall direct contributor to different forms of aggression, supporting the mediating role of depression and trait anger. Depression symptoms explain part of the relationships between PTSD and verbal aggression, physical aggression toward objects, and physical aggression toward self and trait anger explains part of the relationships between PTSD and verbal aggression, physical aggression toward objects, and physical aggression toward others. Our findings support the importance of assessing for anger, depression, and different types of aggression among veterans presenting for PTSD treatment to develop individualized treatment plans that may benefit from early incorporation of interventions.

Spinal cord stimulation in chronic pain: evidence and theory for mechanisms of action

Well-established in the field of bioelectronic medicine, Spinal Cord Stimulation (SCS) offers an implantable, non-pharmacologic treatment for patients with intractable chronic pain conditions. Chronic pain is a widely heterogenous syndrome with regard to both pathophysiology and the resultant phenotype. Despite advances in our understanding of SCS-mediated antinociception, there still exists limited evidence clarifying the pathways recruited when patterned electric pulses are applied to the epidural space. The rapid clinical implementation of novel SCS methods including burst, high frequency and dorsal root ganglion SCS has provided the clinician with multiple options to treat refractory chronic pain. While compelling evidence for safety and efficacy exists in support of these novel paradigms, our understanding of their mechanisms of action (MOA) dramatically lags behind clinical data. In this review, we reconstruct the available basic science and clinical literature that offers support for mechanisms of both paresthesia spinal cord stimulation (P-SCS) and paresthesia-free spinal cord stimulation (PF-SCS). While P-SCS has been heavily examined since its inception, PF-SCS paradigms have recently been clinically approved with the support of limited preclinical research. Thus, wide knowledge gaps exist between their clinical efficacy and MOA. To close this gap, many rich investigative avenues for both P-SCS and PF-SCS are underway, which will further open the door for paradigm optimization, adjunctive therapies and new indications for SCS. As our understanding of these mechanisms evolves, clinicians will be empowered with the possibility of improving patient care using SCS to selectively target specific pathophysiological processes in chronic pain.

Comparative analysis of immunoglobulin IGHD genes in vertebrates

Finding germline immunoglobulin (Ig) V, D, and J genes is a preliminary step in many antibody studies, including development of monoclonal antibody drugs. Recent studies show that the IMGT database, the state-of-the-art database of germline Ig genes, is incomplete for many species. Moreover, modern pharmaceutical studies often involve species not present in the IMGT database (e.g., hamsters, llamas). While V and J genes are conservative and can be inferred by homology, D genes among species are highly diverse. As modern sequencing technologies (Rep-Seq) have enabled scanning millions of antibody RNAs from a single organism, we developed a tool, MINING-D, for de novo inference of functional D genes using Rep-Seq data.

We applied MINING-D to 261 publicly available Rep-Seq datasets: 160 human and 101 non-human datasets, including mouse, rat, rabbit, camel, and rhesus macaque species. Most known D genes, their known and novel variations, and some D genes not presented in the IMGT database were inferred. We further validated a significant number of the novel genes and variations using genomic data.

Thus, our tool circumvents the need of an existing database and infers the functional D genes directly from expressed Ig RNAs. It can potentially speed up the process of antibody sequencing and design of antibody drugs for species with unknown genes. Results from multiple datasets enabled comparative analysis of D genes. For example, while the same germline D genes contribute to the diversity of antibody repertoires in healthy humans, only few of them are used in specific repertoires (e.g., hepatitis) and thus can be critical for recognition of their antigens. We suggest that the obtained results will help in disease monitoring and vaccine design.

Abstract P2-09-08: Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC)

Background: CPI monotherapy provides substantial clinical benefit to patients (pts) in multiple cancers, yet response rates are limited (˜15-30%) and fails to benefit the majority. In these pts there is limited or no ongoing T cell-based immune response. Imprime PGG (Imprime), a novel beta glucan derived from Saccharomyces, may expand the clinical benefit of CPI therapy by stimulating an anti-cancer immune response. Acting as a pathogen-associated molecularpattern (PAMP), Imprime enlists innate immune functions including cytotoxic effector mechanisms, reversal of immunosuppression and cross-talk with the adaptive immune system.Imprime-mediated innate immune activation requires formation of an immune complex with naturally-occurring anti-beta glucan antibodies (ABA); sufficient ABA levels is required for complex formation. Imprime is now being studied in combination with pembrolizumab (KEYTRUDA®,Pembro), a humanized mAb against PD-1 which has been previously studied in TNBC pts.

Methods: In this study of patients who previously failed chemotherapy for metastatic TNBC, Imprime is being used in combination with Pembro in a Simon 2 stage design. Asample size of 12 evaluable pts in Stage 1 was planned.Evaluable pts received at least one dose of study treatment (tx), had measurable disease at baseline per RECIST v1.1, had at least one post-baseline scan or discontinued tx as a result of progressive disease, death, or a tx-related adverse event before the first post-baseline scan.Pts received Imprime (4 mg/kg IV days 1, 8, 15 of each 3-week cycle) + Pembro 200 mg on D1 of each cycle. Criteria to advance to Stage 2 were ≤4 grade 3/4 AEs during the first tx cycle (other than infusion reactions) and ≥1 objective response. Study primary endpoints are ORR and safety; secondary endpoints are TTR, CRR, DoR, PFS, and OS. Exploratory endpoints include ORR and PFS per irRECIST. Biopsies and blood samples are being collected to assess tx impact on immune activating events at the tumor site and in the periphery.

Results: A review of efficacy and safety data was conducted at the end of Stage 1. Thirteen pts (12 evaluable) were enrolled into Stage 1. Safety review noted 2 grade 3 adverse events that met protocol definition of Stage 1 events (1 pt: cellulitis and 1 pt: pleural infusion; both unrelated to treatment). Two events lead to 2 pts discontinuing treatment (infusion reaction and pancreatitis) and only 1 autoimmune event was observed (pancreatitis). Observed efficacy responses in the evaluable pts included 1 complete response (CR; ongoing) and 2 partial responses (PR; ongoing). Secondary efficacy endpoints have not been assessed. Early translational results support proposed MOA and analysis of Stage 1 translational data is ongoing.

Conclusion: The use of Imprime with Pembro was well tolerated and met both safety and efficacy requirements to move forward with Stage 2 of the study. No significant safety concerns were identified in Stage 1. Further investigation is thus warranted and enrollment into Stage 2 is ongoing. Updated data will be presented.

Citation Format: O'Day S, Borges V, Chmielowski B, Rao R, Abu-Khalaf M, Stopeck A, Lowe J, Mattson P, Breuer K, Gargano M, Bose N, Uhlik M, Graff J, Chisamore M, Cox J, Osterwalder B. Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-08.

Noninvasive vagus nerve stimulation alters neural response and physiological autonomic tone to noxious thermal challenge

The mechanisms by which noninvasive vagal nerve stimulation (nVNS) affect central and peripheral neural circuits that subserve pain and autonomic physiology are not clear, and thus remain an area of intense investigation. Effects of nVNS vs sham stimulation on subject responses to five noxious thermal stimuli (applied to left lower extremity), were measured in 30 healthy subjects (n = 15 sham and n = 15 nVNS), with fMRI and physiological galvanic skin response (GSR). With repeated noxious thermal stimuli a group × time analysis showed a significantly (p < .001) decreased response with nVNS in bilateral primary and secondary somatosensory cortices (SI and SII), left dorsoposterior insular cortex, bilateral paracentral lobule, bilateral medial dorsal thalamus, right anterior cingulate cortex, and right orbitofrontal cortex. A group × time × GSR analysis showed a significantly decreased response in the nVNS group (p < .0005) bilaterally in SI, lower and mid medullary brainstem, and inferior occipital cortex. Finally, nVNS treatment showed decreased activity in pronociceptive brainstem nuclei (e.g. the reticular nucleus and rostral ventromedial medulla) and key autonomic integration nuclei (e.g. the rostroventrolateral medulla, nucleus ambiguous, and dorsal motor nucleus of the vagus nerve). In aggregate, noninvasive vagal nerve stimulation reduced the physiological response to noxious thermal stimuli and impacted neural circuits important for pain processing and autonomic output.

Diffuse hepatic haemangiomatosis: A case report and review of literature

Hepatic haemangioma is a solitary liver lesion and prevalent among the female patients. We report a case of diffuse hepatic haemangiomatosis in a 62-year-old man, who was referred for an incidental finding of multiple liver nodules. History and physical examinations were unremarkable. Computed tomography and magnetic resonance imaging of the liver were performed and showed multiple haemangiomatosis. In view of the rarity of this condition in men, a liver biopsy was done and confirmed haemangiomas. Available published literature on diffuse hepatic haemangiomatosis was reviewed.