Role of Cardiovascular Magnetic Resonance in Ischemic Cardiomyopathy.

Ischemic heart disease is the most common cause of cardiovascular morbidity and mortality. Cardiac magnetic resonance (CMR) improves on other noninvasive modalities in detection, assessment, and prognostication of ischemic heart disease. The incorporation of CMR in clinical trials allows for smaller patient samples without the sacrifice of power needed to demonstrate clinical efficacy. CMR can accurately quantify infarct acuity, size, and complications; guide therapy; and prognosticate recovery. Timing of revascularization remains the holy grail of ischemic heart disease, and viability assessment using CMR may be the missing link needed to help reduce morbidity and mortality associated with the disease.

Vascular Thrombosis in COVID-19: A Potential Association with Antiphospholipid Antibodies. A Rapid Systematic Review

BackgroundVascular thrombosis is common in patients with coronavirus disease 2019 (COVID-19). Etiologies underlying this complication are unclear. PurposeTo determine the prevalence of antiphospholipid (aPL), including lupus anticoagulant, anti-cardiolipin and anti-{beta}2-glycoprotein-1 antibodies, and its possible association with thrombotic manifestations of COVID-19. Data SourcesWe searched MEDLINE indexed journals on September 24, 2020 using the tool LitCovid and the pre-print server medRxIV. Study SelectionOriginal investigations (cross-sectional studies, cohort studies, case series, and research letters) on COVID-19 and thrombosis were included. Data ExtractionData were independently extracted, and compiled into spreadsheets based on the PRISMA principles. Data SynthesisHospitalized patients with COVID-19 showed a higher prevalence of lupus anticoagulant compared to non-COVID-19 patients. Temporally, lupus anticoagulant was generally positive early in the course of illness, whereas anti-cardiolipin and anti-{beta}2-glycoprotein-1 antibodies appeared to emerge later in the disease. Some patients who were aPL-negative at an early time-point after disease onset became aPL-positive at a later time-point. Lupus anticoagulant was independently associated with thrombosis in 60 COVID-19 patients in New York had who had 32 thrombotic events (8 arterial and 24 venous). In 88 patients in Wuhan, who had more than 20 each of arterial and venous thrombotic events, medium/high positivity for multiple aPL was significantly associated with arterial thrombosis. However, the association of aPL with thrombosis was not evident in reports that had an overall lower number of or predominantly venous thrombotic events. Analysis of pooled patients revealed that aPL were significantly more frequent in COVID-19 patients with stroke than stroke patients in the general population. Furthermore, injection of IgG aPL fractions from COVID-19 patients into mice accelerated venous thrombosis. LimitationLimited data and paucity of prospective studies. ConclusionThe aPL are prevalent in patients with COVID-19 and their presence is associated with thrombosis. Importantly, these antibodies may be a key mechanism of thrombosis in COVID-19. Follow-up studies are required to understand the relationship between aPL and the spectrum of vascular thrombosis during and after infection with SARS-CoV-2. Primary Funding SourceNone.

Diurnal and seasonal variations in surface methane at a tropical coastal station: Role of mesoscale meteorology.

In view of the large uncertainties in the methane (CH4) emission estimates and the large spatial gaps in its measurements, studies on near-surface CH4 on regional basis become highly relevant. This paper presents the first time observational results of a study on the impacts of mesoscale meteorology on the temporal variations of near-surface CH4 at a tropical coastal station, in India. It is based on the in-situ measurements conducted during January 2014 to August 2016, using an on-line CH4 analyzer working on the principle of gas chromatography. The diurnal variation shows a daytime low (1898-1925ppbv) and nighttime high (1936-2022ppbv) extending till early morning hours. These changes are closely associated with the mesoscale circulations, namely Sea Breeze (SB) and Land Breeze (LB), as obtained through the meteorological observations, WRF simulations of the circulations and the diurnal variation of boundary layer height as observed by the Microwave Radiometer Profiler. The diurnal enhancement always coincides with the onset of LB. Several cases of different onset timings of LB were examined and results presented. The CH4 mixing ratio also exhibits significant seasonal patterns being maximum in winter and minimum in pre-monsoon/monsoon with significant inter-annual variations, which is also reflected in diurnal patterns, and are associated with changing synoptic meteorology. This paper also presents an analysis of in-situ measured near-surface CH4, column averaged and upper tropospheric CH4 retrieved by Atmospheric Infrared Sounder (AIRS) onboard Earth Observing System (EOS)/Aqua which gives insight into the vertical distribution of the CH4 over the location. An attempt is also made to estimate the instantaneous radiative forcing for the measured CH4 mixing ratio.

MoleculeNet: a benchmark for molecular machine learning.

Molecular machine learning has been maturing rapidly over the last few years. Improved methods and the presence of larger datasets have enabled machine learning algorithms to make increasingly accurate predictions about molecular properties. However, algorithmic progress has been limited due to the lack of a standard benchmark to compare the efficacy of proposed methods; most new algorithms are benchmarked on different datasets making it challenging to gauge the quality of proposed methods. This work introduces MoleculeNet, a large scale benchmark for molecular machine learning. MoleculeNet curates multiple public datasets, establishes metrics for evaluation, and offers high quality open-source implementations of multiple previously proposed molecular featurization and learning algorithms (released as part of the DeepChem open source library). MoleculeNet benchmarks demonstrate that learnable representations are powerful tools for molecular machine learning and broadly offer the best performance. However, this result comes with caveats. Learnable representations still struggle to deal with complex tasks under data scarcity and highly imbalanced classification. For quantum mechanical and biophysical datasets, the use of physics-aware featurizations can be more important than choice of particular learning algorithm.

Biliary complications among live donors following live donor liver transplantation.

INTRODUCTION: In live donor liver transplantation (LDLT), bile duct division is a critical step in donor hepatectomy. Biliary complications hence are a feared sequelae even among donors. Long term data on biliary complications in donors from India are sparse. METHODS: Prospective evaluation of 452 live donors over 10 years was performed to ascertain the incidence & risk factors of clinically significant biliary complications. RESULTS: Of the 452 donor hepatectomies (M: F = 114:338, median age = 38), 66.2% (299) were extended right lobe grafts, 24.1% (109) modified right lobe and 9.7% (44) were left lobe grafts. Portal vein anatomy was Type-I in 85% (386), Type-II in 7.5% (34) and Type-III in 7.1% (32). Following donor hepatectomy, a single bile duct opening occurred only in 46.5% (210) of the grafts. Of the remaining 53.5% grafts, 2 ductal openings were noted in 217 (48%) and three ductal openings in 25 (5.5%). Incidence of multiple openings in the duct were more commonly noted in Type II (70.6%) and III (75%) portal vein anatomy than in grafts with Type I (50.4%) portal anatomy (P = 0.001) Bile leak was noted in 15 (3.3%) donors which included one broncho-biliary fistula and bilio-pleural fistula. Analysis revealed no association between post-operative biliary complications and type of graft, portal vein anatomy or biliary anatomy. There was a single mortality in this series secondary to biliary sepsis. On long term follow, there were no biliary strictures in any of the patients. CONCLUSIONS: Biliary complications although rare (3.3%), present significant peri-operative morbidity to the donors.

Low Data Drug Discovery with One-Shot Learning.

Recent advances in machine learning have made significant contributions to drug discovery. Deep neural networks in particular have been demonstrated to provide significant boosts in predictive power when inferring the properties and activities of small-molecule compounds (Ma, J. et al. J. Chem. Inf. MODEL: 2015, 55, 263-274). However, the applicability of these techniques has been limited by the requirement for large amounts of training data. In this work, we demonstrate how one-shot learning can be used to significantly lower the amounts of data required to make meaningful predictions in drug discovery applications. We introduce a new architecture, the iterative refinement long short-term memory, that, when combined with graph convolutional neural networks, significantly improves learning of meaningful distance metrics over small-molecules. We open source all models introduced in this work as part of DeepChem, an open-source framework for deep-learning in drug discovery (Ramsundar, B. deepchem.io. https://github.com/deepchem/deepchem, 2016).

Toxic epidermal necrolysis associated with rifaximin.

PURPOSE: The case of a patient who developed toxic epidermal necrolysis (TEN) after treatment with rifaximin for hepatic encephalopathy is reported. SUMMARY: A 62-year-old Caucasian woman with a history of alcohol abuse arrived at the emergency room with complaints of abdominal pain and acute onset of jaundice, likely secondary to alcoholic hepatitis. Laboratory tests and multiple imaging studies conducted in the emergency department revealed signs of chronic liver disease and common bile duct dilation with ascites. At admission, she had low concentrations of serum sodium, serum chloride, serum creatinine, and serum albumin and elevated liver function test values. On hospital day 7, the patient developed an altered mental status, which was diagnosed as toxic metabolic encephalopathy, primarily hepatic in origin. The patient was given lactulose 20 g via nasogastric tube every 12 hours and rifaximin 400 mg orally every 8 hours. The patient received only two doses of the rifaximin before it was discontinued. On hospital day 27, oral rifaximin 550 mg twice daily was initiated. After 12 days of rifaximin therapy, the patient developed a diffuse, erythematous, maculopapular, and desquamating cutaneous reaction on her chest, arms, and legs. The suspected diagnosis was determined to be a severe cutaneous adverse drug reaction, possibly TEN. Use of the Naranjo et al. scale revealed that rifaximin was a possible cause of the reaction. Rifaximin was discontinued, and antihistamines and i.v. corticosteroids were initiated. The reaction completely resolved after one week. CONCLUSION: A 62-year-old woman developed possible TEN after receiving rifaximin to treat hepatic encephalopathy.

Bilateral scrotal urinary extravasation in a transplant recipient mimicking acute filariasis.

Urinary leak following renal transplantation is less common nowadays with better techniques. Bilateral scrotal extravasation following urinary leak is extremely rare. A history of filariasis in an endemic zone could mask and delay the diagnosis. One such case is described wherein ureteroneocystostomy was revised and the patient could be successfully managed following urinary leak.