bluuebunny/crossref_metadata_2025_split huggingface dataset:
A205 PEMBROLIZUMAB ASSOCIATED SCLEROSING CHOLANGITIS RESPONDS TO COMBINATION OF STEROIDS AND MYCOPHENOLIC ACID: A CASE REPORT
Authors: Zhao X , Huang R , Chen Y , Deschênes M 
Published: March 2021

Abstract

Background
Pembrolizumab is a check point inhibitor that targets programmed cell death receptor ligand 1 (PD-L1). However, check-point inhibitors are associated with its characteristic adverse event know as immune related adverse events that can affect a myriad of organ systems. In the hepatobiliary system, the most commonly described iRAE is hepatitis/hepatotoxicity and latest oncology guidelines offer recommendations on treatment and followup of immunotherapy related hepatitis (1). However, a more rare presentation of iRAE, that have only been described as case reports or case series, is secondary cholangitis. We report one of such a case.

Aims
Case report

Methods
Case report

Results
The patient is a 55 year-old Caucasian female know for lung adenocarcinoma presented to the emergency room on May 5th, 2020, having received her 8th cycle of pembrolizumab. Her blood works mildly elevated transaminitis; ALT 78 U/L, AST 11 U/L, alkaline phosphate of 130 U/L, and total bilirubin of 3.5 umol/L.
MRI of the abdomen showed a normal appearing liver without focal parenchymal lesion, no biliary stones or obstructing masses, dilated common bile duct at 11 mm with small pericholecystic free fluid, and normal gall badder thickness of 2 mm. There was also notion of minimally prominent intrahepatic biliary radicles seen within the CBD.
Etiology workup of cholestatic transaminitis was negative. A diagnosis of immunotherapy related sclerosing cholangitis was posed and the patient was treated with MMF and prednisone with good response.

Conclusions
Discussion
This patient seems to have developed immunotherapy mediated cholangitis. Liver biopsy when performed in liver injury tend to show lobular hepatitis, with liver parenchyma infiltrated with lymphocytes and focal necrosis with acidophilic bodies. However, there seems to be another, less frequent pattern of injury described with pembrolizumab and associated with cholangiopathy, resembling primary biliary cholangitis. It is characterized with portal tracts enlarged with fibrosis and inflammatory cells infiltration; infiltrating cells are lymphocytes (2). Biliary epithelium with fibrosis with CD8+ T cells infiltration seem to be recurrently reported in case reports. (3, 4).
Other cases have been describe in the literature. In many cases, steroid therapy was attempted, but response rates seem to be inconsistent. Nivolumab related cholangitis have been also been described and characterized by extra hepatic bile duct dilatation along with negative immunological markers such as ANA and IgG4 in patients with non-small cell lung cancer, and seems to respond only moderately to steroid therapy (6). Retrospective data of nivolumab related cholangiopathy seems to suggest that there is favourable response to the combination of MMF and steroid therapy (7).

Funding Agencies
None
A233 AGING AND ESOPHAGEAL MOTILITY: A HIGH-RESOLUTION MANOMETRY STUDY
Authors: Djinbachian R , Marchand E , Yan W , Bouin M 
Published: March 2021

Abstract

Background
Studies have found possible physiologic changes to esophageal motility with aging that are not currently taken into account in routine high-definition esophageal manometry (HDEM) interpretation.

Aims
We aimed to quantify the relationship between these physiologic changes and aging to improve HDEM interpretation.

Methods
We conducted a retrospective analysis of medical records for all patients who underwent HDEM at a tertiary hospital center between January 2015 and December 2019. Inclusion criteria were patients ≥18 years with normal HDEM. Exclusion criteria were abnormal HDEM; abnormal upper digestive endoscopy or imagery. Outcomes were median integrated relaxation pressure (IRP); mean lower esophageal sphincter (LES) pressure; mean distal contractal integral (DCI); mean distal latency (DL); mean peristaltic break (PB) according to the v3.0 Chicago classification criteria. Data was extracted from electronic patient medical records into a database for analysis. Effect of age on outcomes was examined through univariate and multivariate linear regression analysis.

Results
We identified 1917 patients with HDEM and included 790 patients with normal exams [mean age 55.8 yrs (IQR 46 – 66), 64% female]. Indications for HDEM included dysphagia (41.3%); gastroesophageal reflux disease (29.2%); chest pain (11.0%); other (13.3%). There was a statistically significant relationship between age and IRP [Coef=0.08 (95%CI 0.05 – 0.1), p&lt;0.001, R^2=0.04] as well as DCI [Coef=10.9 (95%CI 4.1 – 17.8), p=0.002, R^2=0.01] and DL [Coef=-0.01 (95%CI -0.02 – -0.002), p=0.01, R^2=0.008]. No statistically significant relationship was found between age and LES pressure [Coef=0.03 (95%CI -0.01 – 0.08), p=0.16] or PB [Coef=0.007 (95%CI -0.002 – 0.016), p=0.14]. Multivariate analysis showed statistically significant relationships between IRP and age (p&lt;0.001), BMI (p=0.001), NSAID use (p=0.034), and female sex (p=0.048).

Conclusions
We found that IRP, DCI, and DL are significantly correlated with the normal aging process. Modifications could therefore be considered for normal diagnostic cutoffs for both age extremes to prevent over or under-diagnosis of motility disorders.

Funding Agencies
None
A240 HOME PARENTERAL NUTRITION IN OLDER VERSUS YOUNGER PATIENTS: CLINICAL CHARACTERISTICS AND OUTCOMES
Authors: Daoud D , Cartagena E M S , Somlaw N , Schwenger K , Gramlich L , Armstrong D , Raman M , Duerksen D , Whittaker S , Jurewitsch B , Marliss E , Allard J 
Published: March 2021

Abstract

Background
There is a demographic shift toward older patients receiving home parenteral nutrition (HPN) but there is little data on their clinical characteristics and outcomes versus younger HPN patients.

Aims
The objective of this study was to determine if there are any differences between older (&gt; 60 years) and younger (18–59 years) HPN patients in regard to HPN indications, prescriptions and outcomes over the first 2 years receiving HPN.

Methods
This was a retrospective analysis of prospectively collected data from HPN adult patients entered in the password protected web-based Canadian HPN Registry. New HPN patients enrolled between 2003 and 2017 and receiving HPN for 2 years were selected from 8 participating programs across Canada. Data included demographics, anthropometrics, PN prescriptions, line sepsis events, survival and quality of life based on the Karnofsky Performance Status (KPS).

Results
402 patients met the inclusion criteria: 184 patients were 60 years old or above (older group) and 219 patients were between 18 and 59 years old (younger group). Around 64% of both groups were female. There were no significant differences in the main indications for HPN, body mass index (BMI), and PN prescriptions at baseline. At 2-years, younger patients received more calories from PN than older patients (27.88 vs 19.56 Kcal/kg respectively, p &lt;0.001) but BMI remained comparable between groups. There were less line sepsis in the older group versus the younger group (20% vs 36%, p=0.0023) but 78% of younger patients remained alive versus 69 % in the older group (p=0.0401). In those alive, the proportion of patients remaining on HPN was comparable (older group: 77%; younger; group 81%, p=0.4709) and the proportion of patients with a reasonable quality of life (KPS &gt; 60) was similar (older group: 58%; younger group: 63%, p=0.2156).

Conclusions
Older HPN patients have similar clinical characteristics as younger patients but with reduced line sepsis events and higher 2-year mortality.

Funding Agencies
Ontario Medical Supply, Takeda, Fresenius Kabi and Baxter Inc
A245 IGG4- RELATED DISEASE AS A RARE CAUSE OF GASTRIC OUTLET OBSTRUCTION: A CASE REPORT AND LITERATURE REVIEW
Authors: Almudaires A , Alzahrani M , Chen L , Qumosani K 
Published: March 2021

Abstract

Background
IgG4- related disease (IgG4-RD) is a newly recognized systemic fibroinflammatory condition that can affect a wide range of organs, including the pancreas, biliary system, retroperitoneum, lymph nodes and salivary glands. However, gastrointestinal luminal involvement is very rare, and the presentation with isolated gastrointestinal obstruction is extremely unusual.

Aims
We present a case of IgG4-RD presenting with gastric outlet obstruction secondary to severe duodenal stricture.

Methods
A 59-year-old female presented with 6 months history of abdominal pain, postprandial nausea and vomiting associated with significant weight loss. CT showed circumferential wall thickening of the 2ndand 3rd parts of the duodenum with gastroscopy showing severe ulcerated duodenal stricture that could not be passed through. Biopsies from the ulcerated area did not reveal a specific etiology, but malignancy could not be excluded, and the decision was made to pursue surgical management with Whipple’s procedure.
Surgical pathology revealed IgG4 related disease in the form of an ulcerated gastric mass invading the duodenum and the pancreas with normal serum IgG4 level. Postoperatively, the patient developed anastomotic leak that was managed conservatively with antibiotics and drainage resulting in significant improvement in her symptoms. MRCP did not show any pancreatic or biliary abnormalities.

Results
A few weeks later, she represented with abdominal pain as well as nausea and vomiting. CT scan revealed severe inflammatory changes at the anastomosis site with mucosal thickening concerning for persistent leak. However, as she was optimally treated before, it was concluded that these changes are likely related to recurrent IgG4-RD. To induce remission, prednisone was started with remarkable improvement in her symptoms within two weeks, and complete resolution of the previous inflammatory changes around the anastomosis on repeat imaging. Subsequently, she was started on mycophenolate mofetil (MMF) with a slow prednisone taper.

Conclusions
IgG4-RD involving the gastrointestinal tract is rare with rare cases reported in the literature presenting in variable ways. Our case demonstrates the possibility of IgG4-RD presenting as gastric outlet obstruction; IgG4-RD should be considered in the differential diagnosis of unexplained duodenal stricture or gastric outlet obstruction. IgG4-RD usually responds to steroids but long-term response rates to steroid-sparing agents, especially in the subset of patients with luminal IgG4-RD, remains to be seen.

Funding Agencies
None
Long-term variability of root production in bioenergy crops from ingrowth core measurements
Authors: Lei Cheyenne , Abraha Michael , Chen Jiquan , Su Yahn-Jauh 
Published: March 2021

Abstract

Aims
Long-term determination of root biomass production upon land-use conversion to biofuel crops is rare. To assess land-use legacy influences on belowground biomass accumulation, we converted 22-year-old Conservation Reserve Program (CRP) grasslands and 50+-year-old agricultural (AGR) lands to corn (C), switchgrass (Sw) and restored prairie (Pr) biofuel crops. We maintained one CRP grassland as a reference (Ref). We hypothesized that land-use history and crop type have significant effects on root density, with perennial crops on CRP grasslands having a higher root biomass productivity, while corn grown on former agricultural lands produce the lowest root biomass.

Methods
The ingrowth core method was used to determine in situ ingrowth root biomass, alongside measurements of aboveground net primary productivity (ANPP). Ancillary measurements, including air temperature, growing season length and precipitation were used to examine their influences on root biomass production.

Important Findings
Root biomass productivity was the highest in unconverted CRP grassland (1716 g m−2 yr−1) and lowest in corn fields (526 g m−2 yr−1). All perennial sites converted from CRP and AGR lands had lower root biomass and ANPP in the first year of planting but peaked in 2011 for switchgrass and a year later for restored prairies. Ecosystem stability was higher in restored prairies (AGR-Pr: 4.3 ± 0.11; CRP-Pr: 4.1 ± 0.10), with all monocultures exhibiting a lower stability. Root biomass production was positively related to ANPP (R2 = 0.40). Overall, attention should be given to root biomass accumulation in large-scale biofuel production as it is a major source of carbon sequestration.
A forward internal calculus for model generation inS4
Authors: Fiorentini Camillo , Ferrari Mauro 
Published: March 2021

AbstractWe propose an internal calculus to check the satisfiability of a set of formulas in ${\boldsymbol {S4}}$. Our calculus directly supports model extraction and is designed so to implement a forward proof-search strategy that can be understood as a top-down construction of a model. We prove that the extracted models have minimal height.
Labelled cyclic proofs for separation logic
Authors: Galmiche Didier , Méry Daniel 
Published: March 2021

Abstract
Separation logic (SL) is a logical formalism for reasoning about programs that use pointers to mutate data structures. It is successful for program verification as an assertion language to state properties about memory heaps using Hoare triples. Most of the proof systems and verification tools for ${\textrm{SL}}$ focus on the decidable but rather restricted symbolic heaps fragment. Moreover, recent proof systems that go beyond symbolic heaps are purely syntactic or labelled systems dedicated to some fragments of ${\textrm{SL}}$ and they mainly allow either the full set of connectives, or the definition of arbitrary inductive predicates, but not both. In this work, we present a labelled proof system, called ${\textrm{G}_{\textrm{SL}}}$, that allows both the definition of cyclic proofs with arbitrary inductive predicates and the full set of SL connectives. We prove its soundness and show that we can derive in ${\textrm{G}_{\textrm{SL}}}$ the built-in rules for data structures of another non-cyclic labelled proof system and also that ${\textrm{G}_{\textrm{SL}}}$ is strictly more powerful than that system.
Myocardial Bridging, the Hidden Risk Factor for Ischemia
Authors: Happach Vincenzo C , Delk Gerald T , Ganti Latha 
Published: March 2021

ABSTRACT
Myocardial bridging is an uncommon cause of a quite common emergency department complaint for chest pain and is often associated with left ventricular hypertrophy. We present a case of an otherwise healthy middle-aged U.S. military service member who presented with acute coronary syndrome which was ultimately determined to be the result of myocardial bridging.
Variability of newly identified B-type stars observed by Kepler
Authors: Szewczuk Wojciech , Walczak Przemysław , Daszyńska-Daszkiewicz Jadwiga 
Published: March 2021

ABSTRACT
Recent re-determination of stellar atmospheric parameters for a sample of stars observed during the Kepler mission allowed to enlarge the number of Kepler B-type stars. We present the detailed frequency analysis for all these objects. All stars exhibit pulsational variability with maximum amplitudes at frequencies corresponding to high-order g modes. Peaks that could be identified with low-order p/g modes are also extracted for a few stars. We identified some patters in the oscillation spectra that can be associated with the period spacings that can results from the asymptotic nature of the detected pulsational modes. We also tentatively confront the observed oscillation characteristics with predictions from linear non-adiabatic computations of stellar pulsations. For high-order g modes the traditional approximation was employed to include the effects of rotation on the frequency values and mode instability.
ALMA–IRDC – II. First high-angular resolution measurements of the 14N/15N ratio in a large sample of infrared-dark cloud cores
Authors: Fontani F , Barnes A T , Caselli P , Henshaw J D , Cosentino G , Jiménez-Serra I , Tan J C , Pineda J E , Law C Y 
Published: March 2021

ABSTRACT
The 14N/15N ratio in molecules exhibits a large variation in star-forming regions, especially when measured from N2H+ isotopologues. However, there are only a few studies performed at high-angular resolution. We present the first interferometric survey of the 14N/15N ratio in N2H+ obtained with Atacama Large Millimeter Array observations towards four infrared-dark clouds harbouring 3 mm continuum cores associated with different physical properties. We detect N15NH+ (1–0) in $\sim 20\!-\!40{{\ \rm per\ cent}}$ of the cores, depending on the host cloud. The 14N/15N values measured towards the millimetre continuum cores range from a minimum of ∼80 up to a maximum of ∼400. The spread of values is narrower than that found in any previous single-dish survey of high-mass star-forming regions and than that obtained using the total power data only. This suggests that the 14N/15N ratio is on average higher in the diffuse gaseous envelope of the cores and stresses the need for high-angular resolution maps to measure correctly the 14N/15N ratio in dense cores embedded in IRDCs. The average 14N/15N ratio of ∼210 is also lower than the interstellar value at the Galactocentric distance of the clouds (∼300–330), although the sensitivity of our observations does not allow us to unveil 14N/15N ratios higher than ∼400. No clear trend is found between the 14N/15N ratio and the core physical properties. We find only a tentative positive trend between 14N/15N and H2 column density. However, firmer conclusions can be drawn only with higher sensitivity measurements.
Mitigating contamination in LSS surveys: a comparison of methods
Authors: Weaverdyck Noah , Huterer Dragan 
Published: March 2021

ABSTRACTFuture large-scale structure surveys will measure the locations and shapes of billions of galaxies. The precision of such catalogues will require meticulous treatment of systematic contamination of the observed fields. We compare several existing methods for removing such systematics from galaxy clustering measurements. We show how all the methods, including the popular pseudo-Cℓ Mode Projection and Template Subtraction methods, can be interpreted under a common regression framework and use this to suggest improved estimators. We show how methods designed to mitigate systematics in the power spectrum can be used to produce clean maps, which are necessary for cosmological analyses beyond the power spectrum, and we extend current methods to treat the next-order multiplicative contamination in observed maps and power spectra, which reduced power spectrum errors from $\Delta \chi ^2_{\rm C_\ell }\simeq 10$ to ≃ 1 in simulated analyses. Two new mitigation methods are proposed, which incorporate desirable features of current state-of-the-art methods while being simpler to implement. Investigating the performance of all the methods on a common set of simulated measurements from Year 5 of the Dark Energy Survey, we test their robustness to various analysis cases. Our proposed methods produce improved maps and power spectra when compared to current methods, while requiring almost no user tuning. We end with recommendations for systematics mitigation in future surveys, and note that the methods presented are generally applicable beyond the galaxy distribution to any field with spatial systematics.
The PAU Survey: narrow-band photometric redshifts using Gaussian processes
Authors: Soo John Y H , Joachimi Benjamin , Eriksen Martin , Siudek Małgorzata , Alarcon Alex , Cabayol Laura , Carretero Jorge , Casas Ricard , Castander Francisco J , Fernández Enrique , García-Bellido Juan , Gaztanaga Enrique , Hildebrandt Hendrik , Hoekstra Henk , Miquel Ramon , Padilla Cristobal , Sánchez Eusebio , Serrano Santiago , Tallada-Crespí Pau 
Published: March 2021

ABSTRACT
We study the performance of the hybrid template machine learning photometric redshift (photo-z) algorithm delight, which uses Gaussian processes, on a subset of the early data release of the Physics of the Accelerating Universe Survey (PAUS). We calibrate the fluxes of the 40 PAUS narrow bands with six broad-band fluxes (uBVriz) in the Cosmic Evolution Survey (COSMOS) field using three different methods, including a new method that utilizes the correlation between the apparent size and overall flux of the galaxy. We use a rich set of empirically derived galaxy spectral templates as guides to train the Gaussian process, and we show that our results are competitive with other standard photometric redshift algorithms. delight achieves a photo-z 68th percentile error of σ68 = 0.0081(1 + z) without any quality cut for galaxies with iauto &lt; 22.5 as compared to 0.0089(1 + z) and 0.0202(1 + z) for the bpz and annz2 codes, respectively. delight is also shown to produce more accurate probability distribution functions for individual redshift estimates than bpz and annz2. Common photo-z outliers of delight and bcnz2 (previously applied to PAUS) are found to be primarily caused by outliers in the narrow-band fluxes, with a small number of cases potentially indicating spectroscopic redshift failures in the reference sample. In the process, we introduce performance metrics derived from the results of bcnz2 and delight, allowing us to achieve a photo-z quality of σ68 &lt; 0.0035(1 + z) at a magnitude of iauto &lt; 22.5 while keeping 50 per cent objects of the galaxy sample.
Impact of rotation on the evolution of convective vortices in collapsing stars
Authors: Abdikamalov E , Foglizzo T , Mukazhanov O 
Published: March 2021

ABSTRACT
We study the impact of rotation on the hydrodynamic evolution of convective vortices during stellar collapse. Using linear hydrodynamics equations, we study the evolution of the vortices from their initial radii in convective shells down to smaller radii where they are expected to encounter the supernova shock. We find that the evolution of vortices is mainly governed by two effects: the acceleration of infall and the accompanying speed up of rotation. The former effect leads to the radial stretching of vortices, which limits the vortex velocities. The latter effect leads to the angular deformation of vortices in the direction of rotation, amplifying their non-radial velocity. We show that the radial velocities of the vortices are not significantly affected by rotation. We study acoustic wave emission and find that it is not sensitive to rotation. Finally, we analyse the impact of the corotation point and find that it has a small impact on the overall acoustic wave emission.
Interrogating accessibility of telomeric sequences with FRET-PAINT: evidence for length-dependent telomere compaction
Authors: Mustafa Golam , Shiekh Sajad , GC Keshav , Abeysirigunawardena Sanjaya , Balci Hamza 
Published: March 2021

Abstract
Single-stranded telomeric overhangs are ∼200 nucleotides long and can form tandem G-quadruplex (GQ) structures, which reduce their accessibility to nucleases and proteins that activate DNA damage response. Whether these tandem GQs further stack to form compact superstructures, which may provide better protection for longer telomeres, is not known. We report single-molecule measurements where the accessibility of 24–144 nucleotide long human telomeric DNA molecules is interrogated by a short PNA molecule that is complementary to a single GGGTTA repeat, as implemented in the FRET-PAINT method. Binding of the PNA strand to available GGGTTA sequences results in discrete FRET bursts which were analyzed in terms of their dwell times, binding frequencies, and topographic distributions. The binding frequencies were greater for binding to intermediate regions of telomeric DNA compared to 3′- or 5′-ends, suggesting these regions are more accessible. Significantly, the binding frequency per telomeric repeat monotonically decreased with increasing telomere length. These results are consistent with telomeres forming more compact structures at longer lengths, reducing accessibility of these critical genomic sites.