Chemical-physical parameters and microbial community changes induced by electrodes polarization inhibit PCB dechlorination in a marine sediment

Microbial reductive dechlorination of organohalogenated pollutants is often limited by the scarcity of electron donors, that can be overcome with microbial electrochemical technologies (METs). In this study, polarized electrodes buried in marine sediment microcosms were investigated to stimulate PCB reductive dechlorination under potentiostatic (-0.7 V vs Ag/AgCl) and galvanostatic conditions (0.025 mA·cm-2-0.05 mA·cm-2), using graphite rod as cathode and iron plate as sacrificial anode. A single circuit and a novel two antiparallel circuits configuration (2AP) were investigated. Single circuit polarization impacted the sediment pH and redox potential (ORP) proportionally to the intensity of the electrical input and inhibited PCB reductive dechlorination. The effects on the sediment's pH and ORP, along with the inhibition of PCB reductive dechlorination, were mitigated in the 2AP system. Electrodes polarization stimulated sulfate-reduction and promoted the enrichment of bacterial clades potentially involved in sulfate-reduction as well as in sulfur oxidation. This suggested the electrons provided were consumed by competitors of organohalide respiring bacteria and specifically sequestered by sulfur cycling, which may represent the main factor limiting the applicability of METs for stimulating PCB reductive dechlorination in marine sediments.

Site-specific response of sediment microbial community to supplementation of polyhydroxyalkanoates as biostimulants for PCB reductive dechlorination

The use of biodegradable plastics is constantly raising, increasing the likeliness for these polymers to end up in the environment. Environmental applications foreseeing the intentional release of biodegradable plastics have been also recently proposed, e.g., for polyhydroxyalkanoates (PHAs) acting as slow hydrogen releasing compounds to stimulate microbial reductive dehalogenation processes. However, the effects of their release into the environment on the ecosystems still need to be thoroughly explored. In this work, the use of PHAs to enhance the microbial reductive dechlorination of polychlorobiphenyls (PCBs) and their impact on the metabolic and compositional features of the resident microbial community have been investigated in laboratory microcosms of a polluted marine sediment from Mar Piccolo (Taranto, Italy), and compared with recent findings on a different contaminated marine sediment from Pialassa della Baiona (Ravenna, Italy). A decreased biostimulation efficiency of PHAs on PCBs reductive dechlorination was observed in the sediment from Mar Piccolo, with respect to the sediment from Pialassa della Baiona, suggesting that the sediments' physical-chemical characteristics and/or the biodiversity and composition of its microbial community might play a key role in determining the outcome of this biostimulation strategy. Regardless of the sediment origin, PHAs were found to have a specific and pervasive effect on the sediment microbial community, reducing its biodiversity, defining a newly arranged microbial core of primary degraders and consequently affecting, in a site-specific way, the abundance of subdominant bacteria, possibly cross-feeders. Such potential to dramatically change the structure of autochthonous microbial communities should be carefully considered, since it might have secondary effects, e.g., on the natural biogeochemical cycles.

Effect of polyhydroxyalkanoates on the microbial reductive dechlorination of polychlorinated biphenyls and competing anaerobic respirations in a marine microbial culture

The effect of polyhydroxyalkanoates (PHAs) with different composition on the reductive dechlorination activity of a polychlorinated biphenyls (PCBs) dechlorinating marine microbial community and on the activity of sulfate-reducing (SRB) and methanogenic bacteria (MB), were investigated in marine sediment microcosms and compared with the main monomer, 3-hydroxybutyric acid (3HB). Despite PHAs were fermented more slowly than 3HB, all electron donors stimulated constantly sulfate-reduction, methanogenesis and, only transiently, PCB reductive dechlorination. No relevant differences were observed with different compositions of PHAs. According to electron balances, the majority of the supplied electrons (50 %) were consumed by SRB and to less extent by MB (9-31 %), while a small percentage (0.01 %) was delivered to OHRB. In the studied conditions PHAs were confirmed as potential slow‑hydrogen releasing compounds in marine environment but their fermentation rate was sufficiently high to mainly stimulate the competitors of organohalide respring bacteria for electron donors.

Stereotactic arrhythmia radioablation in europe: treatment planning benchmark results of the STOPSTORM consortium

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU

Background

In patients with refractory ventricular tachycardia (VT), STereotactic Arrhythmia Radioablation (STAR) showed promising results for otherwise untreatable patients [1]. The STOPSTORM.eu project coordinates European efforts to clinically validate STAR and to refine protocols and guidelines to ensure treatment harmonization.

Purpose

The aim of this work is to present the current clinical STAR practise in Europe based on three examples as baseline for further optimization.

Methods

Target Volumes (TV) and Organs-at-Risk (OAR) were generated from previous consortium benchmarks and consensus definitions for three well-selected STAR cases [1]. Planning Target Volumes (PTV) were generated based on three different compensation strategies for cardiac and respiratory motion [2] and overlapped close OAR like coronary arteries or stomach in some areas. The STOPSTORM.eu members were asked to generate single fraction treatment plans with 25 Gy dose prescription based on ICRU report 91 for each case based on their clinical practise and preferences for STAR including multi-disciplinary discussion and plan approval. Resulting dose distributions were analysed independently using a customized platform for multi-center treatment planning studies [3].

Results

Twenty centers submitted 22, 23 and 22 treatment plans for case 1, 2 and 3, respectively, mostly (75% of all plans) using Intensity Modulated Arc Therapy (IMAT) with 6 MeV FFF beams (73% of the IMAT plans) among other commonly used techniques for stereotactic radiotherapy. At this current stage, used guidelines for STAR treatment planning and OAR dose limits vary greatly and are mostly based on the AAPM TG-101 report or the RAVENTA trial publication [4]. As a major finding, 73% of all plans submitted preferred close OAR sparing over achieving high PTV coverage arguing that lower doses down to 20 Gy may also result in clinical efficiency as recently suggested [5]. As a minor finding, 80% of the centers chose to override strong artifact regions originating from e.g. left ventricular assist devices.

Conclusion

From this first STOPSTORM.eu multi-center multi-platform treatment planning benchmark study we obtained important information concerning current clinical preference and practise from major European centers performing STereotactic Arrhythmia Radioablation for VT. Using the individual and strongly varying approaches of the centers, the key task for the STOPSTORM.eu project is now to find consensus in order to harmonize and optimize STAR practise in Europe.

P109 CORONARY FLOW VELOCITY RESERVE REDUCTION IS ASSOCIATED WITH CARDIOVASCULAR, CANCER, AND NONCANCER, NONCARDIOVASCULAR MORTALITY

Background

Coronary flow velocity reserve (CFVR) measured in the left anterior descending artery during high–dose vasodilator stress echocardiography interrogates both epicardial and microcirculatory coronary function and has been inversely associated with chronic inflammation and microvascular dysfunction, as well as with the presence of obstructive coronary artery disease. Microvascular dysfunction and chronic inflammation are common mechanisms of disease in cardiovascular (CV) and non–CV conditions. We aimed to assess whether CFVR is associated with all–cause death, but more specifically with CV, cancer, and non–CV and noncancer (NCVNC) mortality, independently and increasingly over other demographic, clinical, and echocardiography variables.

Methods

One thousand two patients who underwent stress echocardiography were followed for a median of 8.2 years, with clinical, regional wall motion abnormalities (RWMAs), and CFVR data. The independent prognostic value of RWMA and CFVR regarding CV, cancer, or NCVNC mortality was evaluated adjusting for clinical variables. A prespecified subgroup of subjects with no RWMA or revascularization procedures during follow–up was also analyzed (n = 752), to exclude most participants with possible coronary artery disease and remove such confounding from the assessment of the potential association of CFVR and mortality.

Results

A total of 161 patients (16%) died, 63 deaths being CV (39%), 52 from cancer (32%), and 46 (29%) from NCVNC causes. In comparison to CV mortality, cancer and NCVNC mortality were not associated with an ischemic RWMA at univariable analysis, while a CFVR < 2 was significantly associated with each category of cause–specific mortality. A CFVR < 2 or ≥ 2 separated a group of patients with 8–year 14.6% versus 1.2% CV mortality, 10.3% versus 0.4% cancer mortality, and 9.5% versus 1.5% NCVNC mortality.

Conclusions

The reduction of CFVR is independently associated with CV, cancer, and NCVNC death in a population clinically referred for suspected/known coronary artery disease. CFVR can act as a marker or a mechanism preceding and predicting mortality from a wide variety of diseases.

1176 Coronary inflammation by CT peri-coronary fat attenuation in MINOCA and Tako-Tsubo syndrome

Funding Acknowledgements

Nothing to declare

OnBehalf

None

Background

Peri-coronary fat attenuation index (pFAI) has emerged as a clinical marker of coronary

inflammation, which is measurable from standard coronary CT angiography (CCTA). It compares

well with gold-standard methods for the assessment of coronary inflammation and can predict future

cardiovascular events. pFAI could prove invaluable to differentiate an inflammatory from noninflammatory coronary artery status, helping unravel the mechanisms subtending an event classified as myocardial infarction with nonobstructive coronary arteries (MINOCA) or Tako-Tsubo syndrome (TTs).

Methods and Results

Patients admitted with MINOCA and TTs diagnosis between 2011 and 2018,

who had both CCTA and CMR performed during or shortly after the acute phase, were selected and

pFAI measured in their index CCTA. pFAI was also measured in a control subjects who had CCTA

for atypical chest pain work-up, no obstructive coronary artery disease found in their CCTA and no

cardiac events at a minimum 2-year follow-up.

In the n = 106 MINOCA/TTs patients selected, mean pFAI averaged for the 3 coronary arteries was -68.37 ± 8.29 vs -78.03 ± 6.20 in the n = 106 controls (p < 0.0001) and the statistical difference was

confirmed also when comparing mean pFAI in each single coronary artery between MINOCA/TTs

and controls (p < 0.0001). Non-obstructive coronary plaques at CCTA, and high-risk plaques in

particular, were also more frequently found (p < 0.01) in the MINOCA/TTs group compared with

controls.

Conclusions

In MINOCA and TTs patients, CCTA is not only able to detect otherwise angiographically invisible atherosclerotic plaques, but its diagnostic yield can be further expanded using the simple off-line measurement of pFAI for the characterization of peri-coronary fat tissue. In MINOCA/TTs mean pFAI clearly demonstrates higher values in comparison with controls, a finding which has been previously associated with coronary artery inflammation. We speculate that this newly-available diagnostic tool in the future may help select patients for new therapies, for example therapies targeting coronary inflammation.

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Abstract 1176 Figure.

P1304 Is antibiotic profilaxis really not needed in mitral valve prolapse?

Conclusion

We reported the case of a severe endocarditic involvement of the mitral valve in a patient with known valvular prolapse, who did not take any antibiotic before a minor dental procedure.

2015 ESC guidelines on Endocarditis recommend to not perform antibiotic prophylaxis in patient with no valvular prosthesis but with other form of valvular disease, including mitral valve prolapse (Class III, level of evidence C). Most of the time, patients with other form of valvular disease (e.g. mitral valve prolapse, bicuspid aortic valve, calcific aortic stenosis) do not experience endocarditis, neither after dental procedures. However, this case shows that sometimes it can happen due to the abnormal conformation of the native valve and, hence, it makes us wonder whether the antibiotic therapy should be indicated before dental procedures in those kind of patients.

Abstract P1304 Figure.

Bladder dose-surface maps and urinary toxicity: Robustness with respect to motion in assessing local dose effects

The purpose of this study was to quantify the impact of inter-fraction modifications of bladder during RT of prostate cancer on bladder dose surface maps (DSM). Eighteen patients treated with daily image-guided Tomotherapy and moderate hypofractionation (70-72.8Gy at 2.5-2.6Gy/fr in 28 fractions and full bladder) were considered. Bladder contours were delineated on co-registered daily Megavoltage CT (MVCT) by a single observer and copied on the planning CT to generate dose-volume/surface histograms (DVH/DSH) and bladder DSMs. Discrepancies between planned and daily absorbed doses were analyzed through the average of individual systematic errors, the population systematic errors and the population random errors for the DVH/DSHs and DSMs. In total, 477 DVH/DSH and 472 DSM were available. DSH and DVH showed small population systematic errors of absolute surfaces (<3.4cm(2)) and volumes (<8.4cm(3)) at the highest doses. The dose to the posterior bladder base assessed on DSMs showed a mean systematic error below 1Gy, with population systematic and random errors within 4 and 3Gy, respectively. The region surrounding this area shows higher mean systematic errors (1-3Gy), population systematic (8-11Gy) and random (5-7Gy) errors. In conclusion, DVH/DSH and DSMs are quite stable with respect to inter-fraction variations in the high-dose region, within about 2cm from bladder base. Larger systematic variations occur in the anterior portion and cranially 2.5-3.5cm from the base. Results suggest that dose predictors related to the high dose area (including the trigone dose) are likely to be sufficiently reliable with respect to the expected variations due to variable bladder filling.

Acupuncture As an Integrative Approach for the Treatment of Hot Flashes in Women With Breast Cancer: A Prospective Multicenter Randomized Controlled Trial (AcCliMaT)

PURPOSE

To determine the effectiveness of acupuncture for the management of hot flashes in women with breast cancer.

PATIENTS AND METHODS

We conducted a pragmatic, randomized controlled trial comparing acupuncture plus enhanced self-care versus enhanced self-care alone. A total of 190 women with breast cancer were randomly assigned. Random assignment was performed with stratification for hormonal therapy; the allocation ratio was 1:1. Both groups received a booklet with information about climacteric syndrome and its management to be followed for at least 12 weeks. In addition, the acupuncture group received 10 traditional acupuncture treatment sessions involving needling of predefined acupoints. The primary outcome was hot flash score at the end of treatment (week 12), calculated as the frequency multiplied by the average severity of hot flashes. The secondary outcomes were climacteric symptoms and quality of life, measured by the Greene Climacteric and Menopause Quality of Life scales. Health outcomes were measured for up to 6 months after treatment. Expectation and satisfaction of treatment effect and safety were also evaluated. We used intention-to-treat analyses.

RESULTS

Of the participants, 105 were randomly assigned to enhanced self-care and 85 to acupuncture plus enhanced self-care. Acupuncture plus enhanced self-care was associated with a significantly lower hot flash score than enhanced self-care at the end of treatment (P < .001) and at 3- and 6-month post-treatment follow-up visits (P = .0028 and .001, respectively). Acupuncture was also associated with fewer climacteric symptoms and higher quality of life in the vasomotor, physical, and psychosocial dimensions (P < .05).

CONCLUSION

Acupuncture in association with enhanced self-care is an effective integrative intervention for managing hot flashes and improving quality of life in women with breast cancer.