Central Arterial Line Placement for Pediatric Cardiac Surgery: A Single-Center Experience.

BACKGROUND: Peripheral arterial line placement is a common, low-risk procedure in pediatric patients undergoing cardiac surgery. Central arterial cannulation may be used when peripheral cannulation is not feasible. At present, there are limited data to guide central arterial-line site selection in pediatric patients. We aimed to (1) quantify the rate of complications associated with central arterial-line placement in pediatric patients undergoing cardiac surgery, (2) determine risk factors associated with central arterial-line complications, and (3) describe placement trends during the last decade. METHODS: This was a retrospective, single-center cohort study of pediatric patients who underwent intraoperative placement of an axillary or femoral arterial line for cardiac surgery between July 1, 2012 and June 30, 2022. The primary outcome studied was the incidence of complications, defined as vascular compromise, pulse loss, ultrasound-confirmed thrombus or flow abnormality, and/or positive blood cultures not attributable to another source. Patients' characteristics and perioperative factors were analyzed using univariate and multivariate analysis to examine the relationship between these factors and line-associated complications. RESULTS: A total of 1263 central arterial lines were analyzed-195 axillary arterial lines and 1068 femoral arterial lines. The overall incidences of vascular compromise and pulse loss from central arterial-line placement were 17.8% and 8.3%, respectively. Axillary lines had lower rates of vascular compromise (6.2% vs 19.9%, P < .001), pulse loss (2.1% vs 9.5%, P < .001), and ultrasound-confirmed thrombus of flow abnormalities (14.3% vs 81.1%, P = .001) than femoral lines. Complications were more common in neonates and infants. By multivariate logistic regression, femoral location (odds ratio [OR], 4.16, 95% confidence interval [CI], 1.97-8.78), presence of a genetic syndrome (OR, 1.68, 95% CI, 1.21-2.34), prematurity (OR, 1.48, 95% CI, 1.02-2.15), and anesthesia time (OR, 1.17 per hour, 95% CI, 1.07-1.27 per hour) were identified as independent risk factors for vascular compromise. Femoral location (OR, 7.43, 95% CI, 2.08-26.6), presence of a genetic syndrome (OR, 1.86, 95% CI, 1.18-2.93), prematurity (OR, 1.65, 95% CI, 1.02-2.67), and 22-G catheter size (OR, 3.26, 95% CI, 1.16-9.15) were identified as independent risk factors for pulse loss. CONCLUSIONS: Axillary arterial access is associated with a lower rate of complications in pediatric patients undergoing cardiac surgery as compared to femoral arterial access. Serious complications are rare and were limited to femoral arterial lines in this study.

Having a chat and then watching a movie: how social interaction synchronises our brains during co-watching.

How does co-presence change our neural experience of the world? Can a conversation change how we synchronise with our partner during later events? Using fNIRS hyperscanning, we measured brain activity from 27 pairs of familiar adults simultaneously over frontal, temporal and parietal regions bilaterally, as they co-watched two different episodes of a short cartoon. In-between the two episodes, each pair engaged in a face-to-face conversation on topics unrelated to the cartoon episodes. Brain synchrony was calculated using wavelet transform coherence and computed separately for real pairs and shuffled pseudo) pairs. Findings reveal that real pairs showed increased brain synchrony over right Dorso-Lateral Pre-Frontal cortex (DLPFC) and right Superior Parietal Lobe (SPL), compared to pseudo pairs (who had never seen each other and watched the same movie at different times; uncorrected for multiple comparisons). In addition, co-watching after a conversation was associated with greater synchrony over right TPJ compared to co-watching before a conversation, and this effect was significantly higher in real pairs (who engaged in conversation with each other) compared to pseudo pairs (who had a conversation with someone else; uncorrected for multiple comparisons). The present study has shed the light on the role of social interaction in modulating brain synchrony across people not just during social interaction, but even for subsequent non-social activities. These results have implications in the growing domain of naturalistic neuroimaging and interactive neuroscience.

MicroRNA 29 modulates ß-cell mitochondrial metabolism and insulin secretion via underlying miR-29-OXPHOS complex pathways.

AIM: MicroRNAs (miRNAs) regulate ß-cell function, and ß-cell mitochondria and insulin secretion are perturbed in diabetes. We aimed to identify key miRNAs regulating ß-cell mitochondrial metabolism and novel ß-cell miRNA-mitochondrial pathways. METHODS: TargetScan (http://www.targetscan.org/) was used to predict if 16 miRNAs implicated in ß-cell function target 27 cis-eGenes implicated in mitochondrial activity. The expression of candidate miRNAs and insulin secretion after 24 and 1 h pre-incubation in 2.8, 11.1- and 16.7-mM glucose was measured in clonal INS-1 832/13 ß-cells. MiR-29 silenced INS-1 832/13 cells were assessed for insulin secretion (glucose, pyruvate, and K+), target cis-eGene expression (Ndufv3 and Ndufa10 components of mitochondrial complex I (CI)), OXPHOS (CI-V) protein expression, and mitochondrial OXPHOS respiration/activity. The expression of differentially expressed miR-29 miRNAs was evaluated in Goto-Kakizaki (GK) rat, db/db mouse and type 2 diabetic (T2D) human islets, as well as NMRI mouse islets cultured under glucolipotoxic conditions. RESULTS: MiR-29, miR-15 and miR-124 were predicted to regulate ~20 cis-eGenes, while miR-29 alone was predicted to regulate ≥12 of these in rat and human species. MiR-29 expression and insulin secretion were reduced in INS-1 832/13 cells after 24 h in elevated glucose. MiR-29 knockdown increased all tested insulin secretory responses, Nudfv3, Ndufa10, complex I and II expression, and cellular mitochondrial OXPHOS. MiR-29 expression was reduced in db/db islets but increased in GK rat and T2D human islets. CONCLUSION: We conclude miR-29 is a key miRNA in regulating ß-cell mitochondrial metabolism and insulin secretion via underlying miR-29-OXPHOS complex pathways. Furthermore, we infer reduced miR-29 expression compensatorily enhances insulin secretion under glucotoxicity.

Quantification of inter-brain coupling: A review of current methods used in haemodynamic and electrophysiological hyperscanning studies.

Hyperscanning is a form of neuroimaging experiment where the brains of two or more participants are imaged simultaneously whilst they interact. Within the domain of social neuroscience, hyperscanning is increasingly used to measure inter-brain coupling (IBC) and explore how brain responses change in tandem during social interaction. In addition to cognitive research, some have suggested that quantification of the interplay between interacting participants can be used as a biomarker for a variety of cognitive mechanisms aswell as to investigate mental health and developmental conditions including schizophrenia, social anxiety and autism. However, many different methods have been used to quantify brain coupling and this can lead to questions about comparability across studies and reduce research reproducibility. Here, we review methods for quantifying IBC, and suggest some ways moving forward. Following the PRISMA guidelines, we reviewed 215 hyperscanning studies, across four different brain imaging modalities: functional near-infrared spectroscopy (fNIRS), functional magnetic resonance (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). Overall, the review identified a total of 27 different methods used to compute IBC. The most common hyperscanning modality is fNIRS, used by 119 studies, 89 of which adopted wavelet coherence. Based on the results of this literature survey, we first report summary statistics of the hyperscanning field, followed by a brief overview of each signal that is obtained from each neuroimaging modality used in hyperscanning. We then discuss the rationale, assumptions and suitability of each method to different modalities which can be used to investigate IBC. Finally, we discuss issues surrounding the interpretation of each method.

The effect of a novel, digital physical activity and emotional well-being intervention on health-related quality of life in people with chronic kidney disease: trial design and baseline data from a multicentre prospective, wait-list randomised controlled trial (kidney BEAM).

BACKGROUND: Physical activity and emotional self-management has the potential to enhance health-related quality of life (HRQoL), but few people with chronic kidney disease (CKD) have access to resources and support. The Kidney BEAM trial aims to evaluate whether an evidence-based physical activity and emotional wellbeing self-management programme (Kidney BEAM) leads to improvements in HRQoL in people with CKD. METHODS: This was a prospective, multicentre, randomised waitlist-controlled trial, with health economic analysis and nested qualitative studies. In total, three hundred and four adults with established CKD were recruited from 11 UK kidney units. Participants were randomly assigned to the intervention (Kidney BEAM) or a wait list control group (1:1). The primary outcome was the between-group difference in Kidney Disease Quality of Life (KDQoL) mental component summary score (MCS) at 12 weeks. Secondary outcomes included the KDQoL physical component summary score, kidney-specific scores, fatigue, life participation, depression and anxiety, physical function, clinical chemistry, healthcare utilisation and harms. All outcomes were measured at baseline and 12 weeks, with long-term HRQoL and adherence also collected at six months follow-up. A nested qualitative study explored experience and impact of using Kidney BEAM. RESULTS: 340 participants were randomised to Kidney BEAM (n = 173) and waiting list (n = 167) groups. There were 96 (55%) and 89 (53%) males in the intervention and waiting list groups respectively, and the mean (SD) age was 53 (14) years in both groups. Ethnicity, body mass, CKD stage, and history of diabetes and hypertension were comparable across groups. The mean (SD) of the MCS was similar in both groups, 44.7 (10.8) and 45.9 (10.6) in the intervention and waiting list groups respectively. CONCLUSION: Results from this trial will establish whether the Kidney BEAM self management programme is a cost-effective method of enhancing mental and physical wellbeing of people with CKD. TRIAL REGISTRATION: NCT04872933. Registered 5th May 2021.

Effect of food additives on key bacterial taxa and the mucosa-associated microbiota in Crohn's disease. The ENIGMA study.

Food additives have been linked to the pro-inflammatory microbial dysbiosis associated with Crohn's disease (CD) but the underlying ecological dynamics are unknown. Here, we examine how selection of food additives affects the growth of multiple strains of a key beneficial bacterium (Faecalibacterium prausnitzii), axenic clinical isolates of proinflammatory bacteria from CD patients (Proteus, Morganella, and Klebsiella spp.), and the consortia of mucosa-associated microbiota recovered from multiple Crohn's disease patients. Bacterial growth of the axenic isolates was evaluated using a habitat-simulating medium supplemented with either sodium sulfite, aluminum silicate, carrageenan, carboxymethylcellulose, polysorbate 80, saccharin, sucralose, or aspartame, intended to approximate concentrations found in food. The microbial consortia recovered from post-operative CD patient mucosal biopsy samples were challenged with either carboxymethylcellulose and/or polysorbate 80, and the bacterial communities compared to unchallenged consortia by 16S rRNA gene amplicon profiling. Growth of all F. prausnitzii strains was arrested when either sodium sulfite or polysorbate 80 was added to cultures at baseline or mid-exponential phase of growth, and the inhibitory effects on the Gram-negative bacteria by sodium sulfite were conditional on oxygen availability. The effects from polysorbate 80, saccharin, carrageenan, and/or carboxymethylcellulose on these bacteria were strain-specific. In addition to their direct effects on bacterial growth, polysorbate 80 and/or carboxymethylcellulose can drive profound changes in the CD mucosa-associated microbiota via niche expansion of Proteus and/or Veillonellaceae - both implicated in early Crohn's disease recurrence. These studies on the interaction of food additives with the enteric microbiota provide a basis for dietary management in Crohn's disease.

Detecting monocyte trafficking in an animal model of glioblastoma using R2* and quantitative susceptibility mapping.

BACKGROUND: The role of tumor-associated macrophages (TAMs) in glioblastoma (GBM) disease progression has received increasing attention. Recent advances have shown that TAMs can be re-programmed to exert a pro-inflammatory, anti-tumor effect to control GBMs. However, imaging methods capable of differentiating tumor progression from immunotherapy treatment effects have been lacking, making timely assessment of treatment response difficult. We showed that tracking monocytes using iron oxide nanoparticle (USPIO) with MRI can be a sensitive imaging method to detect therapy response directed at the innate immune system. METHODS: We implanted syngeneic mouse glioma stem cells into C57/BL6 mice and treated the animals with either niacin (a stimulator of innate immunity) or vehicle. Animals were imaged using an anatomical MRI sequence, R2* mapping, and quantitative susceptibility mapping (QSM) before and after USPIO injection. RESULTS: Compared to vehicles, niacin-treated animals showed significantly higher susceptibility and R2*, representing USPIO and monocyte infiltration into the tumor. We observed a significant reduction in tumor size in the niacin-treated group 7 days later. We validated our MRI results with flow cytometry and immunofluoresence, which showed that niacin decreased pro-inflammatory Ly6C high monocytes in the blood but increased CD16/32 pro-inflammatory macrophages within the tumor, consistent with migration of these pro-inflammatory innate immune cells from the blood to the tumor. CONCLUSION: MRI with USPIO injection can detect therapeutic responses of innate immune stimulating agents before changes in tumor size have occurred, providing a potential complementary imaging technique to monitor cancer immunotherapies. MANUSCRIPT HIGHLIGHT: We show that iron oxide nanoparticles (USPIOs) can be used to label innate immune cells and detect the trafficking of pro-inflammatory monocytes into the glioblastoma. This preceded changes in tumor size, making it a more sensitive imaging technique.

Exploring Noncardiac Surgical Needs From Infancy to Adulthood in Patients With Congenital Heart Disease.

OBJECTIVES: As life expectancy for patients born with congenital heart disease (CHD) continues to rise, these patients will present increasingly for noncardiac surgery during childhood and adolescence. This study aimed to map the lifespan of noncardiac surgical needs among patients with CHD and explore how these needs may change over time. DESIGN: All patients with CHD presenting for noncardiac surgery between 2008 and 2014 were selected for review. SETTING: The study was conducted at a single urban academic tertiary pediatric hospital. PARTICIPANTS: All patients with CHD presenting for noncardiac surgery during the study period were included and grouped by cardiac diagnosis. INTERVENTIONS: Descriptive analysis included patient demographics, CHD diagnosis, procedures performed, and clinical data, including baseline saturation and underlying cardiac function. MEASUREMENTS AND MAIN RESULTS: A total of 3,011 noncardiac surgical procedures were performed on patients with CHD during the study period. The most common CHD diagnoses were patent ductus arteriosus (27.6%), ventricular septal defects (24.7%), and patent foramen ovale (24.3%). The median age was 4 years, 87% of all the patients were ≤10 years, and 41% had associated syndromes. Of the patients, 76% underwent a preoperative echocardiogram, and 10% had depressed cardiac function at the time of surgery. The most common procedures performed were ear, nose, and throat (20%), general surgery (14%), and radiology (11%). Intraoperative events were reported in 488 out of 3,010 encounters (16.2%), with the highest rates reported in patients with single-ventricle physiology (55/179; 30.7%). CONCLUSIONS: These findings suggested a greater burden of noncardiac surgery in lower age groups, with ear, nose, and throat and general surgery most common in young children and orthopedic and dental procedures increasing in adolescence.

Predictions on multi-class terminal ballistics datasets using conditional Generative Adversarial Networks.

Ballistic impacts are a primary risk in both civil and military defence applications, where successfully predicting the dynamic response of a material or structure to impact crucial to the design of safe and fit-for-purpose protective structures. This study proposes a conditional Generative Adversarial Network (cGAN) architecture that can learn directly from available ballistic data and can be conditioned on additional information, such as class labels, to govern its output. A single Multi-Layer Perceptron (MLP) cGAN architecture is trained on a multi-class ballistic training set consisting of 10 classes labelled 0-9 where each class refers to a ballistic curve with a different ballistic limit velocity, vbl. A total of 5 models are trained on datasets consisting of 5, 10, 15, 20 and 25 samples within each class. For integer class labels 0-9, all cGAN models successfully predict the vbl with a maximum error of 4.12%. Additionally, for non-integer class labels between 0-9 the vbl predictions are similar despite not explicitly appearing in the training set. Moreover, each cGAN model is challenged to generate new samples for class labels that exist beyond the scope of the training set for class labels between 9-20. Four of the models predict the vbl with an error of less than 1.5% in all cases. This study showcases how a cGAN model can learn directly from a multi-class ballistic dataset and generate additional samples representative of that data for classes that do not appear explicitly in the training set.

A retrospective review of clinical and non-clinical factors associated with unscheduled cesarean deliveries at one urban medical center.

OBJECTIVE: To investigate factors associated with unscheduled cesarean delivery at one urban tertiary medical center. METHODS: A retrospective chart review was performed on 11 162 deliveries between 2009 and 2019. The dependent variable was unscheduled cesarean delivery. Covariates examined included time of delivery, as well as several maternal and pregnancy-related factors. RESULTS: There were a total of 7037 (63.1%) vaginal, 1133 (10.1%) elective cesarean, and 2992 (26.8%) unscheduled cesarean deliveries. Independent factors associated with increased odds for unscheduled cesarean delivery included daytime delivery (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.18-1.42, P < 0.001); advanced maternal age (OR 1.40, 95% CI 1.26-1.56, P < 0.001); obesity (OR 1.04, 95% CI 1.03-1.05, P < 0.001); history of previous cesarean delivery (OR 2.77, 95% CI 1.91-4.01, P < 0.001); hypertension (OR 1.72, 95% CI 1.27-2.32, P < 0.001); multiparity (OR 3.99, 95% CI 2.82-5.64, P < 0.001); pre-eclampsia (OR 1.96, 95% CI 1.33-2.89, P = 0.001); and HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome (OR 5.45, 95% CI 1.13-26.28, P = 0.035). CONCLUSION: Factors associated with unscheduled cesarean delivery in this study cohort included daytime delivery, advanced maternal age, obesity, hypertension, previous cesarean delivery, multiparity, preterm labor, pre-eclampsia, and HELLP syndrome.

Phase 2 study of anastrozole in rare cohorts of patients with estrogen receptor/progesterone receptor positive leiomyosarcomas and carcinosarcomas of the uterine corpus: The PARAGON trial (ANZGOG 0903).

BACKGROUND: Aromatase inhibitors have been used empirically to treat a subset of patients with hormone receptor positive uterine leiomyosarcomas(LMS) and carcinosarcomas (UCS) mainly supported by retrospective data. We evaluated the activity of anastrozole in two rare cohorts; patients with recurrent/metastatic LMS and UCS enrolled in PARAGON, a basket trial of anastrozole in estrogen receptor (ER+)/progesterone receptor positive (PR+) gynecological cancers. METHOD: An investigator-initiated, single-arm, prospective open-label trial of anastrozole 1 mg/day in patients with ER &/or PR + ve LMS or UCS with measurable disease, treated until progression or unacceptable toxicity. Primary endpoint was clinical benefit (complete/partial response + stable disease) rate (CBR) at 3 months. Secondary endpoints include progression-free survival (PFS), quality of life and toxicity. RESULTS: 39 eligible patients were enrolled, 32 with LMS and 7 with UCS. For the LMS cohort CBR at 3 months was 35% (95% CI: 21-53%) with a median duration of clinical benefit of 5.8 months. Best response was a partial response in one patient. Two patients remained on treatment for more than one year. The median progression-free survival was 2.8 months (95% CI: 2.6-4.9). For the UCS cohort CBR at 3 months was 43% (95% CI: 16-75%) with a median duration of clinical benefit of 5.6 months. Stable disease was seen in 3 patients but no objective responses were seen. The median progression-free survival was 2.7 months (95% CI, 1.1-8.2). Safety was acceptable with 5/39 evaluable patients showing grade 3 toxicities. CONCLUSION: Whilst objective response rates with anastrozole are low, the clinical benefit rate and good tolerance suggests that aromatase inhibitor therapy may have a role in a subset of patients with metastatic LMS and UCS.

Generating a Topological Anomalous Hall Effect in a Nonmagnetic Conductor: An In-Plane Magnetic Field as a Direct Probe of the Berry Curvature.

We demonstrate that the Berry curvature monopole of nonmagnetic two-dimensional spin-3/2 holes leads to a novel Hall effect linear in an applied in-plane magnetic field B_{∥}. Remarkably, all scalar and spin-dependent disorder contributions vanish to leading order in B_{∥}, while there is no Lorentz force and hence no ordinary Hall effect. This purely intrinsic phenomenon, which we term the anomalous planar Hall effect (APHE), provides a direct transport probe of the Berry curvature accessible in all p-type semiconductors. We discuss experimental setups for its measurement.

Novel strain-level resolution of Crohn's disease mucosa-associated microbiota via an ex vivo combination of microbe culture and metagenomic sequencing.

The mucosa-associated microbiota is widely recognized as a potential trigger for Crohn's disease pathophysiology but remains largely uncharacterised beyond its taxonomic composition. Unlike stool microbiota, the functional characterisation of these communities using current DNA/RNA sequencing approaches remains constrained by the relatively small microbial density on tissue, and the overwhelming amount of human DNA recovered during sample preparation. Here, we have used a novel ex vivo approach that combines microbe culture from anaerobically preserved tissue with metagenome sequencing (MC-MGS) to reveal patient-specific and strain-level differences among these communities in post-operative Crohn's disease patients. The 16 S rRNA gene amplicon profiles showed these cultures provide a representative and holistic representation of the mucosa-associated microbiota, and MC-MGS produced both high quality metagenome-assembled genomes of recovered novel bacterial lineages. The MC-MGS approach also produced a strain-level resolution of key Enterobacteriacea and their associated virulence factors and revealed that urease activity underpins a key and diverse metabolic guild in these communities, which was confirmed by culture-based studies with axenic cultures. Collectively, these findings using MC-MGS show that the Crohn's disease mucosa-associated microbiota possesses taxonomic and functional attributes that are highly individualistic, borne at least in part by novel bacterial lineages not readily isolated or characterised from stool samples using current sequencing approaches.

Mitochondrial clearance of calcium facilitated by MICU2 controls insulin secretion.

OBJECTIVE: Transport of Ca2+ into pancreatic ß cell mitochondria facilitates nutrient-mediated insulin secretion. However, the underlying mechanism is unclear. Recent establishment of the molecular identity of the mitochondrial Ca2+ uniporter (MCU) and associated proteins allows modification of mitochondrial Ca2+ transport in intact cells. We examined the consequences of deficiency of the accessory protein MICU2 in rat and human insulin-secreting cells and mouse islets. METHODS: siRNA silencing of Micu2 in the INS-1 832/13 and EndoC-ßH1 cell lines was performed; Micu2-/- mice were also studied. Insulin secretion and mechanistic analyses utilizing live confocal imaging to assess mitochondrial function and intracellular Ca2+ dynamics were performed. RESULTS: Silencing of Micu2 abrogated GSIS in the INS-1 832/13 and EndoC-ßH1 cells. The Micu2-/- mice also displayed attenuated GSIS. Mitochondrial Ca2+ uptake declined in MICU2-deficient INS-1 832/13 and EndoC-ßH1 cells in response to high glucose and high K+. MICU2 silencing in INS-1 832/13 cells, presumably through its effects on mitochondrial Ca2+ uptake, perturbed mitochondrial function illustrated by absent mitochondrial membrane hyperpolarization and lowering of the ATP/ADP ratio in response to elevated glucose. Despite the loss of mitochondrial Ca2+ uptake, cytosolic Ca2+ was lower in siMICU2-treated INS-1 832/13 cells in response to high K+. It was hypothesized that Ca2+ accumulated in the submembrane compartment in MICU2-deficient cells, resulting in desensitization of voltage-dependent Ca2+ channels, lowering total cytosolic Ca2+. Upon high K+ stimulation, MICU2-silenced cells showed higher and prolonged increases in submembrane Ca2+ levels. CONCLUSIONS: MICU2 plays a critical role in ß cell mitochondrial Ca2+ uptake. ß cell mitochondria sequestered Ca2+ from the submembrane compartment, preventing desensitization of voltage-dependent Ca2+ channels and facilitating GSIS.

Working Memory Capacities Neurally Dissociate: Evidence from Acute Stroke.

Substantial behavioral evidence implies the existence of separable working memory (WM) components for maintaining phonological and semantic information. In contrast, only a few studies have addressed the neural basis of phonological versus semantic WM using functional neuroimaging and none has used a lesion-symptom mapping (LSM) approach. Here, we address this gap, reporting a multivariate LSM study of phonological and semantic WM for 94 individuals at the acute stage of left hemisphere stroke. Testing at the acute stage avoids issues of brain reorganization and the adoption of patient strategies for task performance. The LSM analyses for each WM component controlled for the other WM component and semantic and phonological knowledge at the single word level. For phonological WM, the regions uncovered included the supramarginal gyrus, argued to be the site of phonological storage, and several cortical and subcortical regions plausibly related to inner rehearsal. For semantic WM, inferior frontal regions and the angular gyrus were uncovered. The findings thus provide converging evidence for separable systems for phonological and semantic WM that are distinguished from the systems supporting long-term knowledge representations in those domains.

Noninvasive Monitoring of Mantle Cell Lymphoma by Immunoglobulin Gene Next-Generation Sequencing in a Phase 2 Study of Sequential Chemoradioimmunotherapy Followed by Autologous Stem-Cell Rescue.

BACKGROUND: Minimal residual disease (MRD) monitoring has been used to identify early molecular relapse and predict clinical relapse in mantle cell lymphoma (MCL). Few published data exist in MCL on the performance of next-generation sequencing-based assay of immunoglobulin gene rearrangements for MRD assessment. PATIENTS AND METHODS: In a prospective clinical trial (NCT01484093) with intensive induction chemotherapy and autologous stem-cell transplantation, posttreatment peripheral blood samples were collected from 16 MCL patients and analyzed with an earlier version of the Adaptive Biotechnologies MRD assay. RESULTS: Of the 7 patients whose disease remained in remission, the MRD test remained negative in 5 (71%). Of the 9 patients who experienced relapse, the MRD test was positive at least 3 months before relapse in 6 patients (67%) and positive at the time of relapse in 1 patient (11%). All patients with at least 2 positive MRD tests experienced relapse. CONCLUSION: The next-generation sequencing-based MRD assay identified early molecular relapse, and we observed more sensitivity in the cellular (circulating leukocytes) versus acellular (plasma cell-free DNA) compartment. This observation may be due to availability of tumor target or a limitation of the assay.

New signatures of the spin gap in quantum point contacts.

One dimensional semiconductor systems with strong spin-orbit interaction are both of fundamental interest and have potential applications to topological quantum computing. Applying a magnetic field can open a spin gap, a pre-requisite for Majorana zero modes. The spin gap is predicted to manifest as a field dependent dip on the first 1D conductance plateau. However, disorder and interaction effects make identifying spin gap signatures challenging. Here we study experimentally and numerically the 1D channel in a series of low disorder p-type GaAs quantum point contacts, where spin-orbit and hole-hole interactions are strong. We demonstrate an alternative signature for probing spin gaps, which is insensitive to disorder, based on the linear and non-linear response to the orientation of the applied magnetic field, and extract a spin-orbit gap ΔE ≈ 500 µeV. This approach could enable one-dimensional hole systems to be developed as a scalable and reproducible platform for topological quantum applications.

On metal and 'spoiled' wine: analysing psimythion (synthetic cerussite) pellets (5th-3rd centuries BCE) and hypothesising gas-metal reactions over a fermenting liquid within a Greek pot.

A Pb-based synthetic mineral referred to as psimythion (pl. psimythia) was manufactured in the Greek world at least since the 6th c BCE and routinely by the 4th c BCE. Theophrastus (On Stones, 56) describes its preparation from metallic Pb suspended over a fermenting liquid. Psimythion is considered the precursor of one of western art's most prominent white pigments, i.e. lead white (basic lead carbonate or synthetic hydrocerussite). However, so far, and for that early period, published analyses of psimythia suggest that they consisted primarily of synthetic cerussite. In this paper, we set out to investigate how it was possible to manufacture pure cerussite, to the near exclusion of other phases. We examined the chemical and mineralogical composition (pXRF/XRD) of a small number of psimythion pellets found within ceramic pots (pyxis) from Athens and Boeotia (5th-4th c BCE) in the collection of the National Archaeological Museum (NAM), Athens. Analyses showed that the NAM pellets consisted primarily of Pb/cerussite with small amounts of Ca (some samples) and a host of metallic trace elements. We highlight the reference in the Theophrastus text to 'spoiled wine' (oxos), rather than 'vinegar', as has been previously assumed, the former including a strong biotic component. We carried out DNA sequencing of the pellets in an attempt to establish presence of microorganisms (Acetic Acid Bacteria). None was found. Subsequently, and as a working hypothesis, we propose a series of (biotic/abiotic) reactions which were likely to have taken place in the liquid and vapour phases and on the metal surface. The hypothesis aims to demonstrate that CO2 would be microbially induced and would increase, as a function of time, resulting in cerussite forming over and above hydrocerussite/other Pb-rich phases. Psimythion has for long been valued as a white pigment. What has perhaps been not adequately appreciated is the depth of empirical understanding from the part of psimythion manufacturers of the reactions between abiotic and biotic components within 'oxos'/pot, as key drivers of minerals synthesis. Ultimately, psimythion manufacture may rest in understanding the nature of 'oxos', antiquity's relatively little researched strongest acid.