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1.
Int J Cardiol Heart Vasc ; 52: 101381, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38854746

ABSTRACT

Cardiovascular disease is the leading cause of morbidity and mortality in patients with autoimmune rheumatic diseases. Much of this may be attributed to systemic inflammation resulting in coronary atherosclerosis and myocarditis. Cardiac magnetic resonance imaging is the gold standard for the evaluation of cardiac structure and function, including tissue characterization, which allows for detection of myocardial edema, inflammation, and fibrosis. Advances in parametric mapping and coronary flow reserve measurement techniques have the potential to change the diagnosis, risk stratification, and management of patients with autoimmune rheumatic diseases. We provide an overview of the current evidence and suggest potential future roles for the use of comprehensive cardiac magnetic resonance in patients with autoimmune rheumatic diseases in the field of cardio-rheumatology.

2.
Eur Heart J Case Rep ; 8(4): ytae192, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38665427

ABSTRACT

Background: Anomalous aortic origin of a coronary artery from the opposite sinus is a rare congenital abnormality that may be encountered during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). Case summary: A 65-year-old man presented with chest pain and signs of heart failure. Electrocardiogram demonstrated atrial fibrillation with ST elevation in the high lateral leads, and he was taken emergently to the cardiac catheterization laboratory for primary PCI. Coronary angiography identified the culprit to be an occluded anomalous left main coronary artery (LMCA) arising from the right coronary cusp, and primary PCI was successfully performed in the LMCA and the left anterior descending artery (LAD). Computed tomography angiography confirmed a benign retroaortic course of the anomalous LMCA with no additional high-risk features, as well as a new left atrial appendage thrombus. He subsequently developed deep venous thrombosis, acute pulmonary embolism, and acute kidney injury secondary to renal artery embolism with associated infarction. Workup for patent foramen ovale and thrombophilia were negative, and he was discharged in a stable condition. At 2-month follow-up, he was asymptomatic with no evidence of myocardial ischaemia on stress cardiac magnetic resonance imaging. Discussion: We present the first reported case of an occluded anomalous LMCA arising from the right coronary sinus in a patient presenting with STEMI. Rapid recognition of this congenital anomaly and selection of an appropriate guide catheter were keys to achieving timely reperfusion and a good outcome in this case.

5.
J Cardiovasc Magn Reson ; 26(1): 100007, 2024.
Article in English | MEDLINE | ID: mdl-38211509

ABSTRACT

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.


Subject(s)
Cardiovascular Diseases , Predictive Value of Tests , Humans , Cardiovascular Diseases/diagnostic imaging , Cardiovascular Diseases/therapy , Middle Aged , Female , Male , Aged , Magnetic Resonance Imaging , Adult , Prognosis , Young Adult
6.
J Hosp Med ; 19(3): 175-184, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38282424

ABSTRACT

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of severe acute respiratory syndrome coronavirus 2 infection. Features of MIS-C overlap with those of Kawasaki disease (KD). OBJECTIVE: The study objective was to develop a prediction model to assist with this diagnostic dilemma. METHODS: Data from a retrospective cohort of children hospitalized with KD before the coronavirus disease 2019 pandemic were compared to a prospective cohort of children hospitalized with MIS-C. A bootstrapped backwards selection process was used to develop a logistic regression model predicting the probability of MIS-C diagnosis. A nomogram was created for application to individual patients. RESULTS: Compared to children with incomplete and complete KD (N = 602), children with MIS-C (N = 105) were older and had longer hospitalizations; more frequent intensive care unit admissions and vasopressor use; lower white blood cell count, lymphocyte count, erythrocyte sedimentation rate, platelet count, sodium, and alanine aminotransferase; and higher hemoglobin and C-reactive protein (CRP) at admission. Left ventricular dysfunction was more frequent in patients with MIS-C, whereas coronary abnormalities were more common in those with KD. The final prediction model included age, sodium, platelet count, alanine aminotransferase, reduction in left ventricular ejection fraction, and CRP. The model exhibited good discrimination with AUC 0.96 (95% confidence interval: [0.94-0.98]) and was well calibrated (optimism-corrected intercept of -0.020 and slope of 0.99). CONCLUSIONS: A diagnostic prediction model utilizing admission information provides excellent discrimination between MIS-C and KD. This model may be useful for diagnosis of MIS-C but requires external validation.


Subject(s)
COVID-19/complications , Mucocutaneous Lymph Node Syndrome , Systemic Inflammatory Response Syndrome , Child , Humans , Alanine Transaminase , Mucocutaneous Lymph Node Syndrome/complications , Mucocutaneous Lymph Node Syndrome/diagnosis , Prospective Studies , Retrospective Studies , Stroke Volume , Ventricular Function, Left , Sodium
7.
J Am Heart Assoc ; 12(13): e029542, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37345820

ABSTRACT

Background Studies in mice and small patient subsets implicate metabolic dysfunction in cardiac remodeling in aortic stenosis, but no large comprehensive studies of human metabolism in aortic stenosis with long-term follow-up and characterization currently exist. Methods and Results Within a multicenter prospective cohort study, we used principal components analysis to summarize 12 echocardiographic measures of left ventricular structure and function pre-transcatheter aortic valve implantation in 519 subjects (derivation). We used least absolute shrinkage and selection operator regression across 221 metabolites to define metabolic signatures for each structural pattern and measured their relation to death and multimorbidity in the original cohort and up to 2 validation cohorts (N=543 for overall validation). In the derivation cohort (519 individuals; median age, 84 years, 45% women, 95% White individuals), we identified 3 axes of left ventricular remodeling, broadly specifying systolic function, diastolic function, and chamber volumes. Metabolite signatures of each axis specified both known and novel pathways in hypertrophy and cardiac dysfunction. Over a median of 3.1 years (205 deaths), a metabolite score for diastolic function was independently associated with post-transcatheter aortic valve implantation death (adjusted hazard ratio per 1 SD increase in score, 1.54 [95% CI, 1.25-1.90]; P<0.001), with similar effects in each validation cohort. This metabolite score of diastolic function was simultaneously associated with measures of multimorbidity, suggesting a metabolic link between cardiac and noncardiac state in aortic stenosis. Conclusions Metabolite profiles of cardiac structure identify individuals at high risk for death following transcatheter aortic valve implantation and concurrent multimorbidity. These results call for efforts to address potentially reversible metabolic biology associated with risk to optimize post-transcatheter aortic valve implantation recovery, rehabilitation, and survival.


Subject(s)
Aortic Valve Stenosis , Transcatheter Aortic Valve Replacement , Humans , Female , Animals , Mice , Aged, 80 and over , Male , Multimorbidity , Prospective Studies , Treatment Outcome , Aortic Valve/surgery , Ventricular Function, Left
8.
Circ Res ; 132(10): 1387-1404, 2023 05 12.
Article in English | MEDLINE | ID: mdl-37167354

ABSTRACT

Infection with SARS-CoV-2, the virus that causes COVID, is associated with numerous potential secondary complications. Global efforts have been dedicated to understanding the myriad potential cardiovascular sequelae which may occur during acute infection, convalescence, or recovery. Because patients often present with nonspecific symptoms and laboratory findings, cardiac imaging has emerged as an important tool for the discrimination of pulmonary and cardiovascular complications of this disease. The clinician investigating a potential COVID-related complication must account not only for the relative utility of various cardiac imaging modalities but also for the risk of infectious exposure to staff and other patients. Extraordinary clinical and scholarly efforts have brought the international medical community closer to a consensus on the appropriate indications for diagnostic cardiac imaging during this protracted pandemic. In this review, we summarize the existing literature and reference major societal guidelines to provide an overview of the indications and utility of echocardiography, nuclear imaging, cardiac computed tomography, and cardiac magnetic resonance imaging for the diagnosis of cardiovascular complications of COVID.


Subject(s)
COVID-19 , Heart Diseases , Humans , SARS-CoV-2 , COVID-19/diagnostic imaging , COVID-19/complications , Heart , Heart Diseases/etiology , Multimodal Imaging/methods , Magnetic Resonance Imaging
9.
J Am Coll Cardiol ; 81(22): 2149-2160, 2023 06 06.
Article in English | MEDLINE | ID: mdl-37257950

ABSTRACT

BACKGROUND: The impact of Fontan-associated liver disease (FALD) on post-transplant mortality and indications for combined heart-liver transplant (CHLT) in adult Fontan patients remains unknown. OBJECTIVES: The purpose of this study was to assess the impact of FALD on post-transplant outcomes and compare HT vs CHLT in adult Fontan patients. METHODS: We performed a retrospective-cohort study of adult Fontan patients who underwent HT or CHLT across 15 centers. Inclusion criteria were as follows: 1) Fontan; 2) HT/CHLT referral; and 3) age ≥16 years at referral. Pretransplant FALD score was calculated using the following: 1) cirrhosis; 2) varices; 3) splenomegaly; or 4) ≥2 paracenteses. RESULTS: A total of 131 patients (91 HT and 40 CHLT) were included. CHLT recipients were more likely to be older (P = 0.016), have a lower hemoglobin (P = 0.025), require ≥2 diuretic agents pretransplant (P = 0.051), or be transplanted in more recent decades (P = 0.001). Postmatching, CHLT demonstrated a trend toward improved survival at 1 year (93% vs 74%; P = 0.097) and improved survival at 5 years (86% vs 52%; P = 0.041) compared with HT alone. In patients with a FALD score ≥2, CHLT was associated with improved survival (1 year: 85% vs 62%; P = 0.044; 5 years: 77% vs 42%; P = 0.019). In a model with transplant decade and FALD score, CHLT was associated with improved survival (HR: 0.33; P = 0.044) and increasing FALD score was associated with worse survival (FALD score: 2 [HR: 14.6; P = 0.015], 3 [HR: 22.2; P = 0.007], and 4 [HR: 27.8; P = 0.011]). CONCLUSIONS: Higher FALD scores were associated with post-transplant mortality. Although prospective confirmation of our findings is necessary, compared with HT alone, CHLT recipients were older with higher FALD scores, but had similar survival overall and superior survival in patients with a FALD score ≥2.


Subject(s)
Fontan Procedure , Heart Defects, Congenital , Heart Transplantation , Liver Diseases , Liver Transplantation , Humans , Adult , Adolescent , Retrospective Studies , Prospective Studies , Cohort Studies , Fontan Procedure/adverse effects , Liver Diseases/complications , Liver Diseases/surgery , Postoperative Complications/etiology , Heart Defects, Congenital/complications
10.
J Am Coll Cardiol ; 81(22): 2161-2171, 2023 06 06.
Article in English | MEDLINE | ID: mdl-37257951

ABSTRACT

BACKGROUND: An increasing number of adult Fontan patients require heart transplantation (HT) or combined heart-liver transplant (CHLT); however, data regarding outcomes and optimal referral time remain limited. OBJECTIVES: The purpose of this study was to define survivorship post-HT/CHLT and predictors of post-transplant mortality, including timing of referral, in the adult Fontan population. METHODS: A retrospective cohort study of adult Fontan patients who underwent HT or CHLT across 15 centers in the United States and Canada was performed. Inclusion criteria included the following: 1) Fontan; 2) HT/CHLT referral; and 3) age ≥16 years at the time of referral. Date of "failing" Fontan was defined as the earliest of the following: worsening fluid retention, new ascites, refractory arrhythmia, "failing Fontan" diagnosis by treating cardiologist, or admission for heart failure. RESULTS: A total of 131 patients underwent transplant, including 40 CHLT, from 1995 to 2021 with a median post-transplant follow-up time of 1.6 years (Q1 0.35 years, Q3 4.3 years). Survival was 79% at 1 year and 66% at 5 years. Survival differed by decade of transplantation and was 87% at 1 year and 76% at 5 years after 2010. Time from Fontan failure to evaluation (HR/year: 1.23 [95% CI: 1.11-1.36]; P < 0.001) and markers of failure, including NYHA functional class IV (HR: 2.29 [95% CI: 1.10-5.28]; P = 0.050), lower extremity varicosities (HR: 3.92 [95% CI: 1.68-9.14]; P = 0.002), and venovenous collaterals (HR: 2.70 [95% CI: 1.17-6.20]; P = 0.019), were associated with decreased post-transplant survival at 1 year in a bivariate model that included transplant decade. CONCLUSIONS: In our multicenter cohort, post-transplant survival improved over time. Late referral after Fontan failure and markers of failing Fontan physiology, including worse functional status, lower extremity varicosities, and venovenous collaterals, were associated with post-transplant mortality.


Subject(s)
Fontan Procedure , Heart Defects, Congenital , Heart Failure , Heart Transplantation , Liver Transplantation , Humans , Adult , Adolescent , Retrospective Studies , Heart Failure/surgery , Heart Failure/complications , Morbidity , Heart Defects, Congenital/complications
11.
Nano Lett ; 23(10): 4471-4478, 2023 May 24.
Article in English | MEDLINE | ID: mdl-37155184

ABSTRACT

Metal ion intercalation into Group VI transition metal dichalcogenides enables control over their carrier transport properties. In this work, we demonstrate a low-temperature, solution-phase synthetic method to intercalate cationic vanadium complexes into bulk WS2. Vanadium intercalation expands the interlayer spacing from 6.2 to 14.2 Å and stabilizes the 1T' phase of WS2. Kelvin-probe force microscopy measurements indicate that vanadium binding in the van der Waals gap causes an increase in the Fermi level of 1T'-WS2 by 80 meV due to hybridization of vanadium 3d orbitals with the conduction band of the TMD. As a result, the carrier type switches from p-type to n-type, and carrier mobility increases by an order of magnitude relative to the Li-intercalated precursor. Both the conductivity and thermal activation barrier for carrier transport are readily tuned by varying the concentration of VCl3 during the cation-exchange reaction.

12.
JACC Cardiovasc Imaging ; 16(5): 609-624, 2023 05.
Article in English | MEDLINE | ID: mdl-36752429

ABSTRACT

BACKGROUND: Myocardial injury in patients with COVID-19 and suspected cardiac involvement is not well understood. OBJECTIVES: The purpose of this study was to characterize myocardial injury in a multicenter cohort of patients with COVID-19 and suspected cardiac involvement referred for cardiac magnetic resonance (CMR). METHODS: This retrospective study consisted of 1,047 patients from 18 international sites with polymerase chain reaction-confirmed COVID-19 infection who underwent CMR. Myocardial injury was characterized as acute myocarditis, nonacute/nonischemic, acute ischemic, and nonacute/ischemic patterns on CMR. RESULTS: In this cohort, 20.9% of patients had nonischemic injury patterns (acute myocarditis: 7.9%; nonacute/nonischemic: 13.0%), and 6.7% of patients had ischemic injury patterns (acute ischemic: 1.9%; nonacute/ischemic: 4.8%). In a univariate analysis, variables associated with acute myocarditis patterns included chest discomfort (OR: 2.00; 95% CI: 1.17-3.40, P = 0.01), abnormal electrocardiogram (ECG) (OR: 1.90; 95% CI: 1.12-3.23; P = 0.02), natriuretic peptide elevation (OR: 2.99; 95% CI: 1.60-5.58; P = 0.0006), and troponin elevation (OR: 4.21; 95% CI: 2.41-7.36; P < 0.0001). Variables associated with acute ischemic patterns included chest discomfort (OR: 3.14; 95% CI: 1.04-9.49; P = 0.04), abnormal ECG (OR: 4.06; 95% CI: 1.10-14.92; P = 0.04), known coronary disease (OR: 33.30; 95% CI: 4.04-274.53; P = 0.001), hospitalization (OR: 4.98; 95% CI: 1.55-16.05; P = 0.007), natriuretic peptide elevation (OR: 4.19; 95% CI: 1.30-13.51; P = 0.02), and troponin elevation (OR: 25.27; 95% CI: 5.55-115.03; P < 0.0001). In a multivariate analysis, troponin elevation was strongly associated with acute myocarditis patterns (OR: 4.98; 95% CI: 1.76-14.05; P = 0.003). CONCLUSIONS: In this multicenter study of patients with COVID-19 with clinical suspicion for cardiac involvement referred for CMR, nonischemic and ischemic patterns were frequent when cardiac symptoms, ECG abnormalities, and cardiac biomarker elevations were present.


Subject(s)
COVID-19 , Coronary Artery Disease , Heart Injuries , Myocarditis , Humans , Myocarditis/pathology , COVID-19/complications , Retrospective Studies , Predictive Value of Tests , Magnetic Resonance Imaging , Troponin , Magnetic Resonance Spectroscopy
14.
ACR Open Rheumatol ; 4(12): 1050-1059, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36319189

ABSTRACT

OBJECTIVE: Features of multisystem inflammatory syndrome in children (MIS-C) overlap with other syndromes, making the diagnosis difficult for clinicians. We aimed to compare clinical differences between patients with and without clinical MIS-C diagnosis and develop a diagnostic prediction model to assist clinicians in identification of patients with MIS-C within the first 24 hours of hospital presentation. METHODS: A cohort of 127 patients (<21 years) were admitted to an academic children's hospital and evaluated for MIS-C. The primary outcome measure was MIS-C diagnosis at Vanderbilt University Medical Center. Clinical, laboratory, and cardiac features were extracted from the medical record, compared among groups, and selected a priori to identify candidate predictors. Final predictors were identified through a logistic regression model with bootstrapped backward selection in which only variables selected in more than 80% of 500 bootstraps were included in the final model. RESULTS: Of 127 children admitted to our hospital with concern for MIS-C, 45 were clinically diagnosed with MIS-C and 82 were diagnosed with alternative diagnoses. We found a model with four variables-the presence of hypotension and/or fluid resuscitation, abdominal pain, new rash, and the value of serum sodium-showed excellent discrimination (concordance index 0.91; 95% confidence interval: 0.85-0.96) and good calibration in identifying patients with MIS-C. CONCLUSION: A diagnostic prediction model with early clinical and laboratory features shows excellent discrimination and may assist clinicians in distinguishing patients with MIS-C. This model will require external and prospective validation prior to widespread use.

15.
J Am Heart Assoc ; 11(19): e026529, 2022 10 04.
Article in English | MEDLINE | ID: mdl-36172966

ABSTRACT

Background Global longitudinal strain (GLS) is a sensitive measure of left ventricular function and a risk marker in severe aortic stenosis. We sought to determine whether biomarkers of cardiac damage (cardiac troponin) and stress (NT-proBNP [N-terminal pro-B-type natriuretic peptide]) could complement GLS to identify patients with severe aortic stenosis at highest risk. Methods and Results From a multicenter prospective cohort of patients with symptomatic severe aortic stenosis who underwent transcatheter aortic valve implantation, we measured absolute GLS (aGLS), cardiac troponin, and NT-proBNP at baseline in 499 patients. Left ventricular ejection fraction <50% was observed in 19% and impaired GLS (aGLS <15%) in 38%. Elevations in cardiac troponin and NT-proBNP were present in 79% and 89% of those with impaired GLS, respectively, as compared with 63% and 60% of those with normal GLS, respectively (P<0.001 for each). aGLS <15% was associated with increased mortality in univariable analysis (P=0.009), but, in a model with both biomarkers, aGLS, and clinical covariates included, aGLS was not associated with mortality; elevation in each biomarker was associated with an increased hazard of mortality (adjusted hazard ratio, >2; P≤0.002 for each) when the other biomarker was elevated, but not when the other biomarker was normal (interaction P=0.015). Conclusions Among patients with symptomatic severe aortic stenosis undergoing transcatheter aortic valve implantation, elevations in circulating cardiac troponin and NT-proBNP are more common as GLS worsens. Biomarkers of cardiac damage and stress are independently associated with mortality after transcatheter aortic valve implantation, whereas GLS is not. These findings may have implications for risk stratification of asymptomatic patients to determine optimal timing of valve replacement.


Subject(s)
Aortic Valve Stenosis , Transcatheter Aortic Valve Replacement , Aortic Valve/surgery , Biomarkers , Humans , Natriuretic Peptide, Brain , Prospective Studies , Retrospective Studies , Stroke Volume , Transcatheter Aortic Valve Replacement/adverse effects , Troponin , Ventricular Function, Left
16.
Nano Lett ; 22(19): 7811-7818, 2022 Oct 12.
Article in English | MEDLINE | ID: mdl-36130299

ABSTRACT

Achieving superradiance in solids is challenging due to fast dephasing processes from inherent disorder and thermal fluctuations. Perovskite quantum dots (QDs) are an exciting class of exciton emitters with large oscillator strength and high quantum efficiency, making them promising for solid-state superradiance. However, a thorough understanding of the competition between coherence and dephasing from phonon scattering and energetic disorder is currently unavailable. Here, we present an investigation of exciton coherence in perovskite QD solids using temperature-dependent photoluminescence line width and lifetime measurements. Our results demonstrate that excitons are coherently delocalized over 3 QDs at 11 K in superlattices leading to superradiant emission. Scattering from optical phonons leads to the loss of coherence and exciton localization to a single QD at temperatures above 100 K. At low temperatures, static disorder and defects limit exciton coherence. These results highlight the promise and challenge in achieving coherence in perovskite QD solids.

18.
Radiol Cardiothorac Imaging ; 4(4): e210310, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35996735

ABSTRACT

Purpose: To characterize global and segmental circumferential systolic strain (CS) measured by cardiac MRI in athletes after SARS-CoV-2 infection. Materials and Methods: This retrospective observational cohort study included 188 soldiers and collegiate athletes referred for cardiac MRI after SARS-CoV-2 infection (C19+) between July 2020 and February 2021 and a control group of 72 soldiers, collegiate, and high school athletes who underwent cardiac MRI from May 2019 to February 2020, prior to the first SARS-CoV-2 case detected in our region (C19-). Global and segmental CS were measured by feature tracking, then compared between each group using unadjusted and multivariable- adjusted models. Acute myocarditis was diagnosed according to the modified Lake Louise criteria and the location of pathologic late gadolinium enhancement (LGE) was ascertained. Results: Among the 188 C19+ athletes (median age, 25 years [IQR, 23-30]; 131 men), the majority had mild illness. Global CS significantly differed between C19+ and C19- groups, with a median of -24.0 (IQR -25.8, -21.4) versus. -25.0 (-28.0, -22.4), respectively (p = .009). This difference in CS persisted following adjustment for age, sex, body mass index, heart rate, and systolic blood pressure ß coefficient 1.29 [95% CI: 0.20, 2.38], p = .02). In segmental analysis, the basal- and mid- inferoseptal, septal and inferolateral segments were significantly different (p < .05), which had a higher frequency of post-COVID late gadolinium enhancement. The global and segmental differences were similar after exclusion of athletes with myocarditis. Conclusion: Among athletes, SARS-CoV-2 infection was associated with a small but statistically significant reduced CS.

19.
PLoS Pathog ; 18(5): e1010062, 2022 05.
Article in English | MEDLINE | ID: mdl-35588106

ABSTRACT

The diversity of influenza A viruses (IAV) is primarily hosted by two highly divergent avian orders: Anseriformes (ducks, swans and geese) and Charadriiformes (gulls, terns and shorebirds). Studies of IAV have historically focused on Anseriformes, specifically dabbling ducks, overlooking the diversity of hosts in nature, including gull and goose species that have successfully adapted to human habitats. This study sought to address this imbalance by characterizing spillover dynamics and global transmission patterns of IAV over 10 years at greater taxonomic resolution than previously considered. Furthermore, the circulation of viral subtypes in birds that are either host-adapted (low pathogenic H13, H16) or host-generalist (highly pathogenic avian influenza-HPAI H5) provided a unique opportunity to test and extend models of viral evolution. Using Bayesian phylodynamic modelling we uncovered a complex transmission network that relied on ecologically divergent bird hosts. The generalist subtype, HPAI H5 was driven largely by wild geese and swans that acted as a source for wild ducks, gulls, land birds, and domestic geese. Gulls were responsible for moving HPAI H5 more rapidly than any other host, a finding that may reflect their long-distance, pelagic movements and their immuno-naïve status against this subtype. Wild ducks, long viewed as primary hosts for spillover, occupied an optimal space for viral transmission, contributing to geographic expansion and rapid dispersal of HPAI H5. Evidence of inter-hemispheric dispersal via both the Pacific and Atlantic Rims was detected, supporting surveillance at high latitudes along continental margins to achieve early detection. Both neutral (geographic expansion) and non-neutral (antigenic selection) evolutionary processes were found to shape subtype evolution which manifested as unique geographic hotspots for each subtype at the global scale. This study reveals how a diversity of avian hosts contribute to viral spread and spillover with the potential to improve surveillance in an era of rapid global change.


Subject(s)
Charadriiformes , Influenza A virus , Influenza in Birds , Animals , Animals, Wild , Bayes Theorem , Birds , Ducks , Humans , Influenza A virus/genetics
20.
Invest Radiol ; 57(9): 561-566, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35438656

ABSTRACT

OBJECTIVES: We propose a method of quantitatively measuring drug-induced microvascular volume changes, as well as drug-induced changes in blood oxygenation using calibrated blood oxygen level-dependent magnetic resonance imaging (MRI). We postulate that for MRI signals there is a contribution to R2* relaxation rates from static susceptibility effects of the intravascular blood that scales with the blood volume/magnetic field and depends on the oxygenation state of the blood. These may be compared with the effects of an intravascular contrast agent. With 4 R2* measurements, microvascular blood volume (MBV) and tissue oxygenation changes can be quantified with the administration of a vasoactive drug. MATERIALS AND METHODS: The protocol examined 12 healthy rats in a prospective observational study. R2* maps were acquired with and without infusion of adenosine, which increases microvascular blood flow, or dobutamine, which increases myocardial oxygen consumption. In addition, R2* maps were acquired after the intravenous administration of a monocrystalline iron oxide nanoparticle, with and without adenosine or dobutamine. RESULTS: Total microvascular volume was shown to increase by 10.8% with adenosine and by 25.6% with dobutamine ( P < 0.05). When comparing endocardium versus epicardium, both adenosine and dobutamine demonstrated significant differences between endocardial and epicardial MBV changes ( P < 0.05). Total myocardial oxygenation saturation increased by 6.59% with adenosine and by 1.64% with dobutamine ( P = 0.27). The difference between epicardial and endocardial oxygenation changes were significant with each drug (adenosine P < 0.05, dobutamine P < 0.05). CONCLUSIONS: Our results demonstrate the ability to quantify microvascular volume and oxygenation changes using calibrated blood oxygen level-dependent MRI, and we demonstrate different responses of adenosine and dobutamine. This method has clinical potential in examining microvascular disease in various disease states without the administration of radiopharmaceuticals or gadolinium-based contrast agents.


Subject(s)
Coronary Circulation , Dobutamine , Adenosine/pharmacology , Animals , Blood Volume/physiology , Coronary Circulation/physiology , Dobutamine/pharmacology , Rats , Vasodilator Agents/pharmacology
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