Publications by authors named "J Randall Curtis"

3,000 Publications

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Advances in the separation of gangliosides by counter-current chromatography (CCC).

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Apr 9;1174:122701. Epub 2021 Apr 9.

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.

Gangliosides play critical roles in the development of many progressive diseases. Due to their structural diversity, efficient methods are needed to separate individual gangliosides for studies of their functions, and for use as standards in the analysis of ganglioside mixtures. This proof-of-concept study reports a useful analytical-semi-preparative scale counter-current chromatography (CCC) enrichment of multiple ganglioside homologues of various species and classes at the milligram level. Since few individual ganglioside standards were available, this research aimed to achieve analytical-semi-preparative scale separation of gangliosides by differences in saccharide monomer compositions (classes), their arrangements (species), or ceramide compositions (homologues), using CCC. The solvent system composition, addition of solvent modifiers, and elution modes were all adjusted to separate porcine gangliosides, mainly GM1 (d36:1), GD1a (d36:1), GD1b (d36:1) and their (d38:1) homologues as a demonstration. The eluted compounds were analyzed by flow-injection analysis (FIA)-MS and LC-MS/MS. A two-phase solvent system, consisting of butanol/methyl t-butyl ether/acetonitrile/water at a ratio of 2:4:3:8 (v/v/v/v) with 0.5% (v/v) acetic acid added to the lower phase, was used to separate mg-levels of porcine gangliosides under dual-mode elution. The relative abundances of the above 6 gangliosides increased from 10 to 21% in the ganglioside extract to 55-73% in the collected fractions through the purification.
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http://dx.doi.org/10.1016/j.jchromb.2021.122701DOI Listing
April 2021

Predicting In-Hospital Mortality in Patients Undergoing Percutaneous Coronary Intervention.

J Am Coll Cardiol 2021 Apr 28. Epub 2021 Apr 28.

Department of Medicine (Cardiology), University of North Carolina, Chapel Hill, NC. Electronic address:

Background: Standardization of risk is critical in benchmarking and quality improvement efforts for percutaneous coronary interventions (PCI). In 2018, the CathPCI Registry was updated to include additional variables to better classify higher-risk patients.

Objectives: We sought to develop a model for predicting in-hospital mortality risk following PCI incorporating these additional variables.

Methods: Data from 706,263 PCIs performed between 7/2018-6/2019 at 1,608 sites were used to develop and validate a new full and pre-catheterization model to predict in-hospital mortality, and a simplified bedside risk score. The sample was randomly split into a development (70%, n=495,005) and validation cohort (30%, n=211,258). We created 1,000 bootstrapped samples of the development cohort and used stepwise selection logistic regression on each sample. The final model included variables that were selected in at least 70% of the bootstrapped samples and those identified a priori due to clinical relevance.

Results: In-hospital mortality following PCI varied based on clinical presentation. Procedural urgency, cardiovascular instability, and level of consciousness after cardiac arrest were most predictive of in-hospital mortality. The full model performed well, with excellent discrimination (c-index: 0.943) in the validation cohort and good calibration across different clinical and procedural risk cohorts. The median hospital risk-standardized mortality rate was 1.9% and ranged from 1.1% to 3.3% (interquartile range: 1.7%-2.1%).

Conclusions: The risk of mortality following PCI can be predicted in contemporary practice by incorporating variables that reflect clinical acuity. This model, which includes data previously not captured, is a valid instrument for risk stratification and for quality improvement efforts.
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http://dx.doi.org/10.1016/j.jacc.2021.04.067DOI Listing
April 2021

Treatment Strategies for Patients With Immune-Mediated Inflammatory Diseases.

JAMA 2021 May;325(17):1726-1728

University of Pennsylvania Medical Center, Philadelphia.

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http://dx.doi.org/10.1001/jama.2021.2740DOI Listing
May 2021

Social Distancing, Health Care Disruptions, Telemedicine Use, and Treatment Interruption During the COVID-19 Pandemic in Patients With or Without Autoimmune Rheumatic Disease.

ACR Open Rheumatol 2021 May 2. Epub 2021 May 2.

University of Alabama at Birmingham.

Background: We aimed to compare concerns, social distancing, health care disruptions, and telemedicine use in patients with autoimmune rheumatic disease (ARD) and non-ARD and to evaluate factors associated with immunomodulatory medication interruptions.

Methods: Patients in a multistate community rheumatology practice network completed surveys from April 2020 to May 2020. Adults with common ARD (rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus) or non-ARD (gout, osteoarthritis, osteoporosis) were evaluated. Concerns about coronavirus disease 2019 (COVID-19), social distancing, health care disruptions, and telemedicine use were compared in patients with ARD versus non-ARD, adjusting for demographics, rural residence, and zipcode-based measures of socioeconomic status and COVID-19 activity. Factors associated with medication interruptions were assessed in patients with ARD.

Results: Surveys were completed by 2319/36 193 (6.4%) patients with non-ARD and 6885/64 303 (10.7%) with ARD. Concerns about COVID-19 and social distancing behaviors were similar in both groups, although patients receiving a biologic or Janus kinase (JAK) inhibitor reported greater concerns and were more likely to avoid friends/family, stores, or leaving the house. Patients with ARD were less likely to avoid office visits (45.2% vs. 51.0%, odds ratio [OR] 0.79 [0.70-0.89]) with similar telemedicine use. Immunomodulatory medications were stopped in 9.7% of patients with ARD, usually (86.9%) without a physician recommendation. Compared with patients with an office visit, the likelihood of stopping medication was higher for patients with a telemedicine visit (OR 1.54 [1.19-1.99]) but highest for patients with no visits (OR 2.26 [1.79-2.86]).

Conclusion: Patients with ARD and non-ARD reported similar concerns about COVID-19 and similar social distancing behaviors. Missed office visits were strongly associated with interruptions in immunomodulatory medication.
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http://dx.doi.org/10.1002/acr2.11239DOI Listing
May 2021

Defibrillation Safety Margin Testing in Patients With Congenital Heart Disease: Results From the NCDR.

JACC Clin Electrophysiol 2021 Apr 22. Epub 2021 Apr 22.

Section of Cardiac Electrophysiology, Division of Cardiology, University of California-San Diego, La Jolla, California, USA.

Objectives: This study analyzed the predictors of defibrillation safety margin (DSM) testing at the time of implantable cardioverter-defibrillator (ICD) insertion and factors associated with inadequate DSM in patients with congenital heart disease (CHD).

Background: There are few data about the prevalence and safety of DSM testing in those with CHD.

Methods: A retrospective analysis was performed of all patients with atrial or ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, Ebstein anomaly, or common ventricle undergoing a transvenous ICD procedure in the National Cardiovascular Data Registry (NCDR) ICD Registry from April 2010 to March 2016, and DSM testing was assessed. Inadequate DSM was defined as a lowest successful energy tested <10 J than the maximum output of the ICD generator.

Results: Of all ICD recipients (N = 7,024), DSM testing was performed in 52.0% (n = 3,654). The mean lowest successful energy tested was 20.7 ± 7.3 J. Of those with DSM adequacy data available (n = 3,623), an inadequate DSM occurred in 13.8% (n = 501). After multivariable adjustment, DSM testing was not associated with in-hospital complications or death (odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.79 to 1.28) but was associated with lower odds of prolonged hospital stay (>3 days) (OR: 0.71; 95% CI: 0.60 to 0.84; p < 0.0001). An inadequate DSM was not associated with in-hospital death or complications (OR: 1.27; 95% CI: 0.79 to 2.04) or prolonged hospital stay (OR: 1.34; 95% CI: 0.995 to 1.81).

Conclusions: DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes.
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http://dx.doi.org/10.1016/j.jacep.2021.02.019DOI Listing
April 2021