Three-year chronic follow-up from the pilot study of a substernal extravascular implantable cardioverter defibrillator

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Medtronic

Background

The investigational Extravascular Implantable Cardioverter-Defibrillator (EV ICD) uses a substernal lead and delivers defibrillation and pacing therapies, including antitachycardia pacing (ATP).

Objective

To characterize EV ICD system performance through 3 years.

Methods

The prospective, first-in-human EV ICD Pilot study was conducted at 4 sites in Australia and New Zealand. ICD-indicated patients were enrolled July-December of 2018. Defibrillation testing was conducted for all patients at implant, and chronically per physician discretion. Electrical testing was conducted at pre-hospital discharge, 2 weeks, 4-6 weeks and 3 months post-implant, and every 6 months thereafter. Posture effects on pacing and sensing were evaluated through 3 months.

Results

Of 26 patients enrolled, 21 underwent the EV ICD implant procedure. There were no intraprocedural complications. After successful implantation and testing, 17 of 21 patients entered chronic follow-up. 14 patients continue follow up, representing 523 patient-months. Eight elective chronic defibrillation tests converted 7 of 7 patients with ≤ 40 J (maximum energy). Five episodes of spontaneous ventricular tachycardia (VT) were detected in 1 patient and either self-terminated or successfully defibrillated with appropriate shock.

Over the total course of follow-up, 3 patients received an inappropriate shock due to; lead tip displacement with subsequent P-wave oversensing; Electromagnetic interference (EMI) in a ungrounded hot-tub; and EMI while doing plumbing work on unearthed electrical pipes, resulting in an annualized inappropriate shock rate of 6.9%.

Pacing capture thresholds remained stable across time (5.1 ± 2.0 V at implant and 5.5 ± 2.7 V at 3 years); similarly, R-wave amplitudes were stable across time (3.4 ±2.0 mV at implant and 4.2 ± 2.7 mV at 3 years). Pacing thresholds tended to be lowest with the patient lying on the right side and pacing threshold often increased relative to supine position for left-side, prone or bending postures. R-wave amplitude tended to be greater when bending forward.

There were 10 system or procedure-related adverse events in 8 patients through 3 years, including 3 elective system removals for: a single inappropriate shock (1), chronic defibrillation testing showing no safety margin in a patient with arrhythmogenic right ventricular dysplasia (1), intolerance to ATP (1 - high pacing threshold and frequent VT). Other than the lead tip displacement within the first 3 months, no additional clinically significant lead displacements have been observed through 3 years.

Conclusion

The EV ICD is a novel platform for delivering high-voltage therapy. There were no procedure and system related complications observed after the first year post-implant. Lead position and chronic system performance have generally remained stable through 3 years with a low rate of adverse events.

Long term left ventricular impairment after SARS-COV2 infection

Funding Acknowledgements

Type of funding sources: None.

Introduction

The impact of acute infection by SARS-COV2 on the cardiovascular system has been previously reported in the literature, with a higher propensity in patients with more serious pattern of disease and pro-inflammatory status. Nevertheless, the long-term burden and sequels of COVID-19 on the cardiovascular system is still unknown.

Purpose

To evaluate the long-term impact of COVID-19 on left ventricular function in patients with severe clinical presentation requiring intensive care hospitalization.

Methods

 

This was a single-center observational, prospective study which included patients requiring admission to the Intensive Care Unit (ICU) due to COVID-19 infection from January to November 2020. All discharged patients were contacted to perform a clinical, electrocardiographic and echocardiographic evaluation and those who accepted were included on the protocol. Baseline and clinical characteristics were collected from clinical reports. For the global longitudinal strain (GLS) analysis all patients with significant wall motion abnormalities and valvular cardiopathy were excluded. Statistical analysis was performed with Mann-Whitney and a safety cut-off was established with ROC curve analysis.

Results

 

A total of 43 patients were included (mean age 64 ± 12, 67.4% males). During SARS-COV2 infection 49% presented with severe ARDS and 51% with moderate, 35% required invasive mechanical ventilation, 14% noninvasive mechanical ventilation and 52% with high nasal flow cannula. On the follow-up analysis, fatigue was the most reported in symptom (52% patients) and the majority did not present other signs or symptoms suggestive of heart failure, with the mean NT-proBNP of 49 ± 389 pg/dL. The standard ECG and echocardiogram did not show significant changes with a mean LVEF of 58 ± 7.8 and mean TAPSE of 21 ± 4. The strain analysis showed low value of GLS (mean GLS of -17.14 ± 2.36) for a reference cut-off of -18%, suggesting subclinical left ventricular dysfunction in this subset of patients with preserved ejection fraction. Maximum CPR values during ICU did not correlate either with the extent of disease evolvement in CT (p= NS) or ARDS severity (p= NS). Nevertheless, maximum CPR correlated significantly with GLS reduction (R = 0.44, p = 0.019). A CPR value higher than iger30mg/dL had 100% specificity for GLS reduction and a cut-off of 14gm/dL reported a sensitivity of 65% and specificity pf 75% for reduction in GLS.

Conclusion

In our study, we reported subclinical impairment in left ventricular function detected with global longitudinal strain after serious infection with SARS-COV2. The detected myocardial dysfunction was related with higher inflammatory as expressed by CPR values. Long-term monitoring of these patients should be undertaken in order to timely detect late complications. Abstract Figure.

Regression of left ventricular mass after transcatheter aortic valve implantation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Regression of left ventricular mass (LVM) after transcatheter aortic valve implantation (TAVI) is an important parameter of left ventricular reverse remodeling and is associated with less hospitalizations 1year after TAVI. The association between LVM índex (LVMi) at 6 months and outcome 1 year after TAVI is unclear.

Purpose

Evaluate and compare LVMi, before TAVI and 6 months after, and determine the association between LVMi regression and clinical outcomes at 1-year follow-up.

Methods

Retrospective, comparative study in patients with symptomatic severe aortic stenosis with a high operative risk, after TAVI. All patients underwent echocardiographic study before TAVI and 6 months of follow-up, the LVMi (by the Devereux formula) was evaluated. Associations between LVMi regression (percent change between baseline and 6 months after TAVI), rehospitalization rate and death at 1 year of follow-up were examined.

Results

We studied 50 patients, 82% with moderade or severe LVMi before TAVI. Comparative analysis between ecocardiography study before and 6 months after TAVI, showed there was statistically significant decrease in LVMi (150,7 ± 38 g/m2 vs 132 ± 36 g/m2; p = 0.03). LVMi moderate or severe (between 130 and 154 g/m2) at 6 months was associated with biggest hospitalization rate (p = 0,03).Comparative analysis between regression of LVMi (before and 6 months after TAVI) and death, showed: decrease of 5% and 10% in LVMi was independently associated with death at 1 year (p = 0,77 vs p = 0,4).

Conclusions

Patients with severe symptomatic aortic stenosis treated with TAVI who had a significant decrease of LVMi after 6 months of follow-up had lower hospitalization rates, but decrease of LVMi is independently associated with death at 1 year of follow-up.

Short-term outcomes of minimally invasive retromuscular ventral hernia repair using an enhanced view totally extraperitoneal (eTEP) approach: systematic review and meta-analysis

Background

The enhanced view totally extraperitoneal (eTEP) approach is becoming increasingly more widely accepted as a promising technique in the treatment of ventral hernia. However, evidence is still lacking regarding the perioperative, postoperative and long-term outcomes of this technique. The aim of this meta-analysis is to summarize the current available evidence regarding the perioperative and short-term outcomes of ventral hernia repair using eTEP.

Study design

A systematic search was performed of PubMed, EMBASE, Cochrane Library and Web of Science electronic databases to identify studies on the laparoscopic or robotic-enhanced view totally extraperitoneal (eTEP) approach for the treatment of ventral hernia. A pooled meta-analysis was performed. The primary end point was focused on short-term outcomes regarding perioperative characteristics and postoperative parameters.

Results

A total of 13 studies were identified involving 918 patients. Minimally invasive eTEP resulted in a rate of surgical site infection of 0% [95% CI 0.0–1.0%], a rate of seroma of 5% [95% CI 2.0–8.0%] and a rate of major complications (Clavien–Dindo III–IV) of 1% [95% CI 0.0–3.0%]. The rate of intraoperative complications was 2% [95% CI 0.0–4.0%] with a conversion rate of 1.0% [95% CI 0.0–3.0%]. Mean hospital length of stay was 1.77 days [95% CI 1.21–2.24]. After a median follow-up of 6.6 months (1–24), the rate of recurrence was 1% [95% CI 0.0–1.0%].

Conclusion

Minimally invasive eTEP is a safe and effective approach for ventral hernia repair, with low reported intraoperative complications and good outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10029-021-02557-8.

Hear us! Accounts of people treated with injectables for drug-resistant TB

BACKGROUND

WHO drug-resistant TB (DR-TB) treatment recommendations now emphasize all-oral regimens, recommending against certain injectable agents and deprioritizing others due to inferior safety and efficacy. Despite increasing focus on patient-centered care, we are not aware of systematic attempts to qualitatively document patients' perspectives on injectable agents. This may inform implementation of WHO guidelines, emphasizing the importance of consultation with affected communities.

METHODS

Testimonies were provided by TB survivors who experienced hearing loss from treatment with injectable agents. Testimonies were submitted in writing in response to minimal, standardized, open-ended prompts. Participants provided a signed consent form (with options to participate anonymously or as a named co-author), and later gave input into the overall shape and recommendations of the article.

RESULTS

Fourteen TB survivors in 12 countries contributed testimonies. The following common themes emerged: lack of access to appropriate testing, information, treatment, or a collaborative treatment environment; the power of supportive care and social environments; stigma and isolation from TB treatment itself and resultant disability; and inaccessibility of cochlear implants.

CONCLUSIONS

Survivor testimonies indicate strong preferences for avoidance of injectable agents, supporting rapid implementation of revised WHO guidelines, as well as for quality and supportive care for both TB and disabilities.

Urine biomonitoring of glyphosate in children: Exposure and risk assessment

The use of glyphosate has been increasing over the years, making it one of the most consumed herbicides in the world. Although children are considered a vulnerable population, only four previous published studies determined glyphosate in the urine of non-occupationally exposed children. The paucity of epidemiological data and biomonitoring surveys are considered major gaps, that hinder the implementation of science driven policies in the protection of public health. The aim of the present study was to determine glyphosate in the urine of 41 Portuguese children (2-13 years old) and identify potential determinants of exposure. Glyphosate was detected in 95.1% of the samples (1.77 ± 0.86 μg/L), up to a maximum value of 4.35 μg/L. Glyphosate concentrations were higher in the urine of children aged 7-9 years, living near agricultural areas (<1 km), with a higher percentage of consumption of home-produced foods, and whose parents applied herbicides in the backyard. Risk assessment revealed an exposure representing 1-5.58% of the established Acceptable Daily Intake (ADI) of glyphosate (0.5 mg/kg bw/day). The results should be further analyzed considering the age of the participants, for which no adjusted ADI exists. This was the first published report of glyphosate exposure in the urine of Portuguese children.

Strain relaxation dynamics of multiferroic orthorhombic manganites

Resonant ultrasound spectroscopy has been used to characterise strain coupling and relaxation behavior associated with magnetic/magnetoelectric phase transitions in GdMnO₃, TbMnO₃and TbMn_0.98Fe_0.02O₃through their influence on elastic/anelastic properties. Acoustic attenuation ahead of the paramagnetic to colinear-sinusoidal incommensurate antiferromagnetic transition at ∼41 K correlates with anomalies in dielectric properties and is interpreted in terms of Debye-like freezing processes. A loss peak at ∼150 K is related to a steep increase in electrical conductivity with a polaron mechanism. The activation energy,E_a, of ≳0.04 eV from a loss peak at ∼80 K is consistent with the existence of a well-defined temperature interval in which the paramagnetic structure is stabilised by local, dynamic correlations of electric and magnetic polarisation that couple with strain and have relaxation times in the vicinity of ∼10^-6s. Comparison with previously published data for Sm_0.6Y_0.4MnO₃confirms that this pattern may be typical for multiferroic orthorhombicRMnO₃perovskites (R= Gd, Tb, Dy). A frequency-dependent loss peak near 10 K observed for TbMnO₃and TbMn_0.98Fe_0.02O₃, but not for GdMnO₃, yieldedE_a⩾ ∼0.002 eV and is interpreted as freezing of some magnetoelastic component of the cycloid structure. Small anomalies in elastic properties associated with the incommensurate and cycloidal magnetic transitions confirm results from thermal expansion data that the magnetic order parameters have weak but significant coupling with strain. Even at strain magnitudes of ∼0.1-1‰, polaron-like strain effects are clearly important in defining the development and evolution of magnetoelectric properties in these materials. Strains associated with the cubic-orthorhombic transition due to the combined Jahn-Teller/octahedral tilting transition in the vicinity of 1500 K are 2-3 orders of magnitude greater. It is inevitable that ferroelastic twin walls due to this transition would have significantly different magnetoelectric properties from homogeneous domains due to magnetoelastic coupling with steep strain gradients.

Effects of single and combined exposures of gold (nano versus ionic form) and gemfibrozil in a liver organ culture of Sparus aurata

In vitro methods have gained rising importance in ecotoxicology due to ethical concerns. The aim of this study was to assess the single and combined in vitro effects of gold, as nanoparticle (AuNPs) and ionic (Au⁺) form, and the pharmaceutical gemfibrozil (GEM). Sparus aurata liver organ culture was exposed to gold (4 to 7200 μg·L^-1), GEM (1.5 to 15,000 μg·L^-1) and combination 80 μg·L^-1 gold +150 μg·L^-1 GEM for 24 h. Endpoints related with antioxidant status, peroxidative/genetic damage were assessed. AuNPs caused more effects than Au⁺, increasing catalase and glutathione reductase activities and damaging DNA and cellular membranes. Effects were dependent on AuNPs size, coating and concentration. GEM damaged DNA at an environmentally relevant concentration, 1.5 μg·L^-1. Overall, the effects of the combined exposures were higher than the predicted, based on single exposures. This study showed that liver culture can be a useful model to study contaminants effects.

The Situation Room as a management tool: the case of the Municipal Health Secretariat of Salvador

Problem

The Salvador Municipal Health Secretariat (MHS) utilizes health data to elaborate technical documents to manage and respond to instances requiring internal or external control. In answer to demands for the modernization and transparency of municipal management, the constitution of a Health Situation Room (HSR) was included in the political agenda of the Secretary, thereby guaranteeing political, technical and operational support for its implementation.

Description of the Problem

To describe the process of construction of the HSR in the Salvador MHS in 2020. The HSR is a physical, virtual and collective space for the analysis of information, which begins with a data search which allows to understand the information flow, identifying the solicitor and the constructor of the information, the data source and the informational object itself.

Results

130 technicians and managers were interviewed, and their responses then categorized into 161 indicators across different themes. The results point out the need to define a spatial analysis unit to be adopted, and to communicate with external actors who demand information, as well as to develop a communication plan for the HSR.

Lessons

To develop an informational culture oriented by local and central protagonism, generating evidence for decision-making and information transparency for the whole of society.

Key messages

The Health Situation Room reduces the time between information-decision-action. The Health Situation Room prioritizes interdisciplinary collaboration and increases the efficiency of the health system.

Utility assessment of an Enzyme-linked immunosorbent assay for detection of subclinical cases of caseous lymphadenitis in small ruminant flocks

The actual prevalence of CLA (caseous lymphadenitis) in small ruminant flocks is underestimated in many countries, and because it is not a notifiable disease, it will continue to spread without data and information about its real economic impact. The difficulty in the accurate identification of the causative agent in internal subclinical cases allows the disease to spread within and between flocks. This research intends to assess the utility of an ELISA (enzyme‐linked immunosorbent assay) test in the detection of internal subclinical cases of CLA in farms and to simultaneously add data on the seroprevalence of the disease in Portugal. Sera from 756 small ruminants, 70% sheep (528/756) and 30% goats (228/756) were screened for antibodies against Corynebacterium pseudotuberculosis using the ELISA technique based on a recombinant phospholipase D (ELITEST CLA # CK105A^®). The animals showing internal lesions (n ꞊ 58) were sampled for the identification of the aetiological agent. In this investigation, the prevalence of CLA was 34% (258/756), with the ELISA test showing a low specificity (78%) and high sensitivity (100%). The proof was able to detect 57% (13/23) of subclinical cases of CLA confirmed by postmortem examination and conventional PCR (polymerase chain reaction). The results also reveal that goats have a higher propensity for the disease, and dairy farms and non‐extensive production units appear to be more susceptible to CLA. This research clarifies an actual problem and pointed out the importance of CLA in small ruminant herds in Portugal. Finally seems to demonstrate that the ELISA test is a good diagnostic tool for use in CLA eradication programmes.

AB0406 HUMAN PAPILLOMA VIRUS (HPV) VACCINATION SAFETY IN SYSTEMIC LUPUS ERYTHEMATOSUS COHORT - PORTUGUESE UNIVERSITY HOSPITAL SINGLE-CENTER COHORT STUDY

Background:

Cervical cancer is a potentially preventable consequence of Human Papillomavirus (HPV). HPV vaccination is recommended in most countries for all young women, preferentially before sexual activity begins. In Portugal, HPV vaccination is available in either bivalent (genotypes 6, 18) or tetravalent (6, 11, 16 e 18) vaccines. Both have aluminum as an adjuvant, a substance arguably capable of inducing inflammatory adjuvant syndromes. Systemic Lupus Erythematosus (SLE) mostly afflicts women of childbearing age, the very target population for HPV vaccination. There are conflicting reports in the literature regarding both the efficacy and safety of this vaccine in SLE patients. This question is particularly pressing as HPV infection prevalence seems to be increased in SLE patients.

Objectives:

To analyze the safety of HPV vaccination in a SLE patient cohort followed at a university hospital.

Methods:

Retrospective single-center (35 year long, 436 SLE patient cohort) review of all female SLE patients’ local and online national records on HPV vaccination and cervical cancer screening. Data on activity (using SLEDAI-2K scoring) and concomitant drug use were reviewed for the two years before and after vaccination date.

Results:

Of the 463 SLE patients, 420 were women (91%), of which 322 had clinical information about yes/no HPV vaccination. Twenty-seven of the patients (8%) had one of HPV vaccines, but only 13 (4%) had full information on activity before and after vaccination. Mean current age was 33,8 years and a minimum of 8,4 years of follow-up after HPV vaccination. Twenty-there (85%) were vaccinated with the tetravalent vaccine. Pre-vaccination mean SLEDAI score of was 5.9: due to arthritis (n= 5; 38,5%), low complement (n=4; 31%), dsDNA (n=4; 31%); with a medium dose of 10mg prednisolone/day and 265mg/day of hydroxychloroquine. Post-vaccination mean SLEDAI was 5.8: due to arthritis (n=6; 46%), rash (n= 5; 38,5%) and low complement (n=6; 46%); with a medium dose of 8mg prednisolone/day and 288mg/day of hydroxychloroquine. There was not a difference in organ involvement before and after vaccination, but rash was slightly more prevalent after vaccination.

Conclusion:

In our population, HPV vaccination didn’t significantly change disease activity and organ involvement or mean dose need of prednisolone or hydroxychloroquine. Although it is a small size SLE sample, it suggests that is safe to administer HPV vaccination to SLE patients.

References:

[1]eularSegal Yahel, Zabludowicz Center for Autoimmune Diseases, Tel Aviv (2017), “HPV and systemic lupus erythematosus: a mosai of potential crossreaction”, SLE Research and Clinical Update, 23 January 2017

[2]Geier David Institute of Chronic Illnesses, USA, (2016), “Quadrivalent human pappilomavirus vaccine and autoimmune adverse events: a case-control assessment of the vaccine adverse event reporting system (VAERS) database, Environment and Autoimmunity, 13 July 2016

Disclosure of Interests: :

None declared

AB0407 HUMAN PAPILLOMA VIRUS (HPV) INFECTION AND CERVICAL CANCER PREVALENCE IN A PORTUGUESE UNIVERSITY HOSPITAL SINGLE-CENTER SYSTEMIC LUPUS ERYTHEMATOSUS COHORT

Background:

About 12% of women worldwide are infected with Human Papillomavirus (HPV), the most frequent cause of cervical cancer (CC) - very prevalent (~ 7,5%) and preventable. National screening efforts are in use in several countries, including Portugal. Patients with Systemic Lupus Erythematosus (SLE) are at increased risk of HPV infection and CC when compared to the healthy population.

Objectives:

To evaluate the prevalence of HPV infection and rate of incidence of cervical neoplastic lesions in a SLE patient cohort followed at a university hospital.

Methods:

Retrospective single-center (35 year long, 463 SLE patient cohort) review of all female SLE patients’ local and online national health care records on HPV vaccination and CC screening.

Results:

Of the 463 SLE patients, 420 were women (91%), of which 322 had records on of HPV infection or CC developed. Mean patients’ current age was 48 years and all had screening for cervical pathology in the last 3 years. Thirty-three patients (11%) had HPV infection diagnosed at a mean age of 44 years. Twenty-seven (8%) of SLE patients were vaccinated for HPV: 8 (22%) of the infected patients had the vaccine, half after the HPV infection. Despite HPV infection, 49 patients (15%) had developed some cervical lesion, of which 41 (84% of cervical lesion) were suggestive of malignancy, and ultimately CC was diagnosed in 20 women (41%; 6% of total women), with a mean age at diagnosis of 45 years. All CC patients had history of HPV infection, but only 3 women (15%; 0,9% of total women) had been vaccinated against HPV, 2 after the diagnoses of CC and 1 before.

Conclusion:

In our population the prevalence of HPV was higher than reported for the general population using the World Health Organization database, conforming the higher risk of HPV infection in SLE patients. The prevalence of cervical cancer, however, was similar to the healthy population.

References:

[1]https://www.who.int/immunization/diseases/hpv/en/

[2]Forman David (2012); “Global Burden of Human Papillomavirus and Related Diseases”, Vaccine, Elsevier Volume 30, Supplement 5, 20 November 2012

[3]Grein Ingrid (2016), Department of Pediatric Immunology and Rheumatology, Netherland (2016), HPV infection and vaccination in Systemic Lupus Erythematosus patients: what we really should know, Pediatric Rheumatology, 2016

Disclosure of Interests: :

None declared

1272 Control of Sleep-Associated Respiratory Distress with a Mandibular Advancement Oral Appliance in an Unusual Case of a Patient with a Mild Rather Persistent Nocturnal Baseline Hypoventilation/Hypoxia

Introduction

Normal respiratory function is crucial for adequate sleep. Sleep Related Breathing Disorders, namely Obstructive Sleep Apnea (OSA) are frequent conditions among a large spectrum of obstructive events in the upper airway which are often linked to significant sleep related oxyhemoglobin dessaturation levels compared to those observed in baseline PSG-oximetry recorded. On the other hand, low baseline oxygen saturation (LBOS) is commonly linked to symptomatic cardiorespiratory disturbances which may adversely impact respiratory outcomes either awake or during sleep. Therefore it is relevant to be aware of the baseline ventilatory status in order to optimize the therapeutic care.

Report of Case

We present an unusual case of a patient with moderate OSA which was successfully controlled with a Mandibular Advancement Oral Appliance (OAm). Despite the control with the OAm, the patient still maintained a nocturnal pattern of hypoventilation/hypoxia. The 53 yo female patient with normal weight/height ratio (BMI=25,2) complaining of non restorative sleep, tiredness, impaired memory, excessive diurnal sleepiness (Epworth Sleepiness Scale - ESS=10 and bruxism with a PSG diagnosis of moderate OSA (BaselineO2Sat=94%; IAH=17,4 ev/h; ODI=32,9 ev/h; T90=34,7% of TST) was referred for treatment with a OAm. A PM Type 1 positioner was inserted and titrated until 12 mm of advancement (80% of maximal measured protrusion). Within 6 months follow up and after clinical titration, there was a clear symptomatic and objective improvement with resolution of all major complaints including sleepiness (ESS=5). Titration PSG showed a normalization in all parameters (IAH=1,4 ev/h;ODI=4 ev/h;T90=0,1% of TST). Baseline O2 Sat however remained low (93%) in the titration PSG even though no symptoms or signs of a disorder existed even after discounting for Ph related metabolic changes (normal levels of HCO3)

Conclusion

This is an interesting case of an unusual patient who presented with a LBOS level in the diagnostic PSG. Despite the therapeutic success of the OAm in controlling the sleep related respiratory condition, measured by all otherwise normalized PSG based sleep and respiratory parameters, maintained a LBOS in the titration PSG without any signs or symptoms of disease.

Biological effects and bioaccumulation of gold in gilthead seabream (Sparus aurata) - Nano versus ionic form

The question of whether gold (Au) is more toxic as nanoparticles or in its ionic form remains unclear and controversial. The present work aimed to clarify the effects of 96 h exposure to 4, 80 and 1600 μg·L^-1 of 7 nm gold nanoparticles (AuNPs) - (citrate coated (cAuNPs) or polyvinylpyrrolidone coated (PVP-AuNPs)) - and ionic Au (iAu) on gilthead seabream (Sparus aurata). Effects at different levels of biological organization (behaviour, neurotransmission, biotransformation, oxidative stress/damage and genotoxicity) were assessed. cAuNPs induced oxidative stress and damage (lipid peroxidation increase), even at 4 μg·L^-1, and reduced the ability of S. aurata to swim against a water flow at 1600 μg·L^-1. Exposure to cAuNPs induced more adverse effects than exposure to PVP-AuNPs. All tested concentrations of Au (nano or ionic form) induced DNA breaks and cytogenetic damage in erythrocytes of S. aurata. Generally, iAu induced significantly more effects in fish than the nano form, probably associated with the significantly higher accumulation in the fish tissues. No fish mortality was observed following exposure to AuNPs, but mortality was observed in the group exposed to 1600 μg·L^-1 of iAu.