The mechanisms by which Geobacter sulfurreducens transfers electrons through relatively thick (>50 microm) biofilms to electrodes acting as a sole electron acceptor were investigated. Biofilms of ...Geobacter sulfurreducens were grown either in flow-through systems with graphite anodes as the electron acceptor or on the same graphite surface, but with fumarate as the sole electron acceptor. Fumarate-grown biofilms were not immediately capable of significant current production, suggesting substantial physiological differences from current-producing biofilms. Microarray analysis revealed 13 genes in current-harvesting biofilms that had significantly higher transcript levels. The greatest increases were for pilA, the gene immediately downstream of pilA, and the genes for two outer c-type membrane cytochromes, OmcB and OmcZ. Down-regulated genes included the genes for the outer-membrane c-type cytochromes, OmcS and OmcT. Results of quantitative RT-PCR of gene transcript levels during biofilm growth were consistent with microarray results. OmcZ and the outer-surface c-type cytochrome, OmcE, were more abundant and OmcS was less abundant in current-harvesting cells. Strains in which pilA, the gene immediately downstream from pilA, omcB, omcS, omcE, or omcZ was deleted demonstrated that only deletion of pilA or omcZ severely inhibited current production and biofilm formation in current-harvesting mode. In contrast, these gene deletions had no impact on biofilm formation on graphite surfaces when fumarate served as the electron acceptor. These results suggest that biofilms grown harvesting current are specifically poised for electron transfer to electrodes and that, in addition to pili, OmcZ is a key component in electron transfer through differentiated G. sulfurreducens biofilms to electrodes.
Objectives
Quality of life studies in recurrent respiratory papillomatosis (RRP) have traditionally relied upon clinician‐designed survey instruments. This study's objective is to report quality of ...life outcomes from a patient‐designed questionnaire.
Methods
Patients who provided health information and completed a quality of life questionnaire were identified from the RRPF‐CoRDS patient registry. Demographic, clinical, and quality of life measures were collected. Means and standard deviations were calculated for continuous data, and frequencies and percentages were calculated for categorical data. Outcomes for patients with juvenile‐onset RRP (JORRP) and adult‐onset RRP (AORRP) were compared using Student's t‐tests for continuous data and χ2 analyses for categorical data.
Results
Seventy‐three patients with RRP were identified (JORRP: 32; AORRP: 41). Common clinical symptoms included raspy voice (78.1%) and dyspnea (61.6%). The majority (97.3%) of patients reported feeling debilitated by their diagnosis, and 94.5% of patients reported avoiding participation in career and/or social activities due to their voice quality. Due to their RRP, 65.7% reported missing at least five work days each month. Social anxiety was reported in 79.5% of patients, though only 28.8% of the cohort reported utilizing mental health services. The median (range) lifetime number of surgeries received was 20 (1 ‐ 300). Most patients (57.5%) reported paying at least 5% of their annual income towards RRP‐related medical care.
Conclusion
RRP presents high mental and fiscal burden. Our results highlight data from a quality of life questionnaire designed by RRP patients, and may help to elucidate potential disconnects between what clinicians and RRP patients consider most impactful.
Level of Evidence
4 Laryngoscope, 133:1919–1926, 2023
Quality of life outcomes for patients with recurrent respiratory papillomatosis have traditionally been derived from clinician‐designed survey instruments. In this manuscript, we are the first to describe quality of life data from a questionnaire designed by patients and other stakeholders of the Recurrent Respiratory Papillomatosis Foundation. The results of our study highlight the significant medical, mental, and fiscal burden faced by patients with recurrent respiratory papillomatosis.
After a reperfused myocardial infarction (MI), dynamic tissue changes occur (edema, inflammation, microvascular obstruction, hemorrhage, cardiomyocyte necrosis, and ultimately replacement by ...fibrosis). The extension and magnitude of these changes contribute to long-term prognosis after MI. Cardiac magnetic resonance (CMR) is the gold-standard technique for noninvasive myocardial tissue characterization. CMR is also the preferred methodology for the identification of potential benefits associated with new cardioprotective strategies both in experimental and clinical trials. However, there is a wide heterogeneity in CMR methodologies used in experimental and clinical trials, including time of post-MI scan, acquisition protocols, and, more importantly, selection of endpoints. There is a need for standardization of these methodologies to improve the translation into a real clinical benefit. The main objective of this scientific expert panel consensus document is to provide recommendations for CMR endpoint selection in experimental and clinical trials based on pathophysiology and its association with hard outcomes.
The use of T2-weighted MR imaging to delineate the area at risk and subsequently quantify myocardial salvage is problematic on many levels. The validation studies available thus far are inadequate. ...Unlike the data validating DE MR imaging, in which pathologic analysis has shown the precise shape and contour of the bright region exactly match the infarcted area, this level of validation does not exist for T2-weighted MR imaging. Technical advances have occurred, but image contrast between abnormal and normal regions remains limited, and in this situation, measured size differences between MR imaging data sets should not be overinterpreted. Moreover, with any T2 technique, there remains the key issue that there is no physiologic basis for the apparent T2 findings. Indeed, a homogeneously bright area at risk on T2-weighted MR images is incompatible with the known levels of edema that occur in infarcted and salvaged myocardium, and the finding that the lateral borders of T2 hyperintense regions frequently extend far beyond that of infarction is contrary to the wavefront phenomenon. Even if T2-weighted MR imaging provided an accurate measure of myocardial edema, the level of edema within the area at risk is dependent on multiple variables, including infarct size, age, reperfusion status, reperfusion injury, and therapies that could have an antiedema effect. The area at risk is a coronary perfusion territory. There is a fundamental limitation with defining the area at risk by using a nonperfusion-based indicator that can vary with different postreperfusion therapies. There are several applications for T2 myocardial imaging, including differentiation of acute from chronic MI and identification of acute myocarditis. On the basis of the currently available data; however, we conclude that T2-weighted MR imaging should not be used to delineate the area at risk in patients with ischemic myocardial injury.
This study sought to determine the prevalence, correlates, and impact on cardiac mortality of right ventricular (RV) dysfunction in nonischemic cardiomyopathy.
Current heart failure guidelines place ...little emphasis on RV assessment due to limited available data on determinants of RV function, mechanisms leading to its failure, and relation to outcomes.
We prospectively studied 423 patients with cardiac magnetic resonance (CMR). The pre-specified study endpoint was cardiac mortality. In 100 patients, right heart catheterization was performed as clinically indicated.
During a median follow-up time of 6.2 years (interquartile range: 2.9 to 7.6 years), 101 patients (24%) died of cardiac causes. CMR right ventricular ejection fraction (RVEF) was a strong independent predictor of cardiac mortality after adjustment for age, heart failure–functional class, blood pressure, heart rate, serum sodium, serum creatinine, myocardial scar, and left ventricular ejection fraction (LVEF). Patients with the lowest quintile of RVEF had a nearly 5-fold higher cardiac mortality risk than did patients with the highest quintile (hazard ratio: 4.68; 95% confidence interval CI: 2.43 to 9.02; p < 0.0001). RVEF was positively correlated with LVEF (r = 0.60; p < 0.0001), and inversely correlated with right atrial pressure (r = −0.32; p = 0.001), pulmonary artery pressure (r = −0.34; p = 0.0005), transpulmonary gradient (r = −0.28; p = 0.006) but not with pulmonary wedge pressure (r = −0.15; p = 0.13). In multivariable logistic regression analysis of CMR, clinical, and hemodynamic data the strongest predictors of right ventricular dysfunction were LVEF (odds ratio OR: 0.85; 95% CI: 0.78 to 0.92; p < 0.0001), transpulmonary gradient (OR: 1.20; 95% CI: 1.09 to 1.32; p = 0.0003), and systolic blood pressure (OR: 0.97; 95% CI: 0.94 to 0.99; p = 0.02).
CMR assessment of RVEF provides important prognostic information independent of established risk factors and LVEF in heart failure patients with nonischemic cardiomyopathy. Right ventricular dysfunction is strongly associated with both indices of intrinsic myocardial contractility and increased afterload from pulmonary vascular dysfunction.
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Recent studies reported left ventricular (LV) fibrosis in patients with primary mitral regurgitation (MR) thought to be principally due to mitral valve prolapse (MVP).
This study sought to evaluate ...the prevalence, characteristics, and prognostic implications of LV fibrosis in a large cohort of primary MR patients with and without MVP using cardiovascular magnetic resonance (CMR).
Patients referred for contrast CMR assessment of chronic primary MR were enrolled and underwent comprehensive assessment of cardiac remodeling, severity of MR, and LV replacement fibrosis. Primary MR patients were stratified into: an MVP group if there was >2 mm mitral leaflet displacement on cine-CMR, or a non-MVP group. Patients were followed for arrhythmic events (sudden cardiac death, aborted sudden cardiac arrest, and sustained or inducible ventricular arrhythmia).
A total of 356 primary MR patients (177 MVP and 179 non-MVP) were enrolled. LV fibrosis was more prevalent in the MVP group than the non-MVP group (36.7% vs. 6.7%; p < 0.001). The presence of MVP had the strongest association (odds ratio: 6.82; p < 0.001) with LV fibrosis even after adjustment for clinical variables, measures of cardiac remodeling, and MR severity. During follow-up (median 1,354 days), MVP patients with LV fibrosis had the highest event rate for arrhythmic events.
In primary MR patients, LV fibrosis is more prevalent in MVP than non-MVP, suggesting a unique pathophysiology beyond volume overload in MVP. LV fibrosis in primary MR may represent a risk marker of arrhythmic events.
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In patients with sarcoidosis, sudden death is a leading cause of mortality, which may represent unrecognized cardiac involvement. Delayed-enhancement cardiovascular magnetic resonance (DE-CMR) can ...detect minute amounts of myocardial damage. We sought to compare DE-CMR with standard clinical evaluation for the identification of cardiac involvement.
Eighty-one consecutive patients with biopsy-proven extracardiac sarcoidosis were prospectively recruited for a parallel and masked comparison of cardiac involvement between (1) DE-CMR and (2) standard clinical evaluation with the use of consensus criteria (modified Japanese Ministry of Health JMH guidelines). Standard evaluation included 12-lead ECG and at least 1 dedicated non-CMR cardiac study (echocardiography, radionuclide scintigraphy, or cardiac catheterization). Patients were followed for 21+/-8 months for major adverse events (death, defibrillator shock, or pacemaker requirement). Patients were predominantly middle-aged (46+/-11 years), female (62%), and black (73%) and had chronic sarcoidosis (median, 7 years) and preserved left ventricular ejection fraction (median, 56%). DE-CMR identified cardiac involvement in 21 patients (26%) and JMH criteria in 10 (12%, 8 overlapping), a >2-fold higher rate for DE-CMR (P=0.005). All patients with myocardial damage on DE-CMR had coronary disease excluded by x-ray angiography. Pathology evaluation in 15 patients (19%) identified 4 with cardiac sarcoidosis; all 4 were positive by DE-CMR, whereas 2 were JMH positive. On follow-up, 8 had adverse events, including 5 cardiac deaths. Patients with myocardial damage on DE-CMR had a 9-fold higher rate of adverse events and an 11.5-fold higher rate of cardiac death than patients without damage.
In patients with sarcoidosis, DE-CMR is more than twice as sensitive for cardiac involvement as current consensus criteria. Myocardial damage detected by DE-CMR appears to be associated with future adverse events including cardiac death, but events were few, and this needs confirmation in a larger cohort.
International news can inform people not only about what is happening in other countries, but also about how their own country could benefit from policies that have proved successful elsewhere. ...Specifically, international policy comparison news, or news that compares the policies of two or more countries on the same issue, is a potentially important but underutilized and understudied form of news content. We use an experiment to test effects of exposure to news comparing the COVID-19 pandemic policies of the U.S. versus South Korea, and find that this increases knowledge of policy differences between the two countries, support for adopting similar policies in the U.S., presidential blame for the severity of the pandemic in the U.S., and trust in health experts. On most outcomes, these effects did not vary across political party lines, a particularly encouraging result given the polarized nature of policy debates on this issue.
Background To determine if hot, humid ambient conditions impact filtering facepiece respirators' (FFRs') fit, and to evaluate differences in physiologic and subjective responses between N95 FFRs and ...P100 FFRs. Methods Twelve subjects had physiologic monitoring and subjective perceptions monitored over 1 hour of treadmill exercise (5.6 km/h) in an environmental chamber (35°C, relative humidity 50%) wearing an N95 FFR, P100 FFR, or no respirator. Respirator quantitative fit testing was done before and after exercise. Results There was no significant difference in pass rates for both FFRs on initial fit testing, but subjects who passed were more likely to fail the postexercise test with N95 FFRs ( P = .01). Wearing FFRs increased the temperature of facial skin covered by the FFR ( P = .009) and breathing discomfort ( P = .002). No significant differences were noted in other measured variables (heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide level, rectal temperature, global skin temperature, core temperature, and subjective perceptions) between controls and FFRs and between FFR models. Conclusion After 1 hour of exercise in hot, humid ambient conditions, P100 FFRs retained better fit than N95 FFRs, without additional physiologic or subjective impact. Wearing FFRs under these conditions does not add to the body's thermophysiologic or perceptual burdens.
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