COVID-19 vaccines and adverse events of special interest: A multinational Global Vaccine Data Network (GVDN) cohort study of 99 million vaccinated individuals.

BACKGROUND: The Global COVID Vaccine Safety (GCoVS) Project, established in 2021 under the multinational Global Vaccine Data Network™ (GVDN®), facilitates comprehensive assessment of vaccine safety. This study aimed to evaluate the risk of adverse events of special interest (AESI) following COVID-19 vaccination from 10 sites across eight countries. METHODS: Using a common protocol, this observational cohort study compared observed with expected rates of 13 selected AESI across neurological, haematological, and cardiac outcomes. Expected rates were obtained by participating sites using pre-COVID-19 vaccination healthcare data stratified by age and sex. Observed rates were reported from the same healthcare datasets since COVID-19 vaccination program rollout. AESI occurring up to 42 days following vaccination with mRNA (BNT162b2 and mRNA-1273) and adenovirus-vector (ChAdOx1) vaccines were included in the primary analysis. Risks were assessed using observed versus expected (OE) ratios with 95 % confidence intervals. Prioritised potential safety signals were those with lower bound of the 95 % confidence interval (LBCI) greater than 1.5. RESULTS: Participants included 99,068,901 vaccinated individuals. In total, 183,559,462 doses of BNT162b2, 36,178,442 doses of mRNA-1273, and 23,093,399 doses of ChAdOx1 were administered across participating sites in the study period. Risk periods following homologous vaccination schedules contributed 23,168,335 person-years of follow-up. OE ratios with LBCI > 1.5 were observed for Guillain-Barré syndrome (2.49, 95 % CI: 2.15, 2.87) and cerebral venous sinus thrombosis (3.23, 95 % CI: 2.51, 4.09) following the first dose of ChAdOx1 vaccine. Acute disseminated encephalomyelitis showed an OE ratio of 3.78 (95 % CI: 1.52, 7.78) following the first dose of mRNA-1273 vaccine. The OE ratios for myocarditis and pericarditis following BNT162b2, mRNA-1273, and ChAdOx1 were significantly increased with LBCIs > 1.5. CONCLUSION: This multi-country analysis confirmed pre-established safety signals for myocarditis, pericarditis, Guillain-Barré syndrome, and cerebral venous sinus thrombosis. Other potential safety signals that require further investigation were identified.

Open-label, phase II, multicenter study of lasofoxifene plus abemaciclib for treating women with metastatic ER+/HER2- breast cancer and an ESR1 mutation after disease progression on prior therapies: ELAINE 2.

BACKGROUND: Acquired ESR1 mutations in estrogen receptor-positive (ER+) metastatic breast cancer (mBC) drive treatment resistance and tumor progression; new treatment strategies are needed. Lasofoxifene, a next-generation, oral, endocrine therapy and tissue-specific ER antagonist, provided preclinical antitumor activity, alone or combined with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) in ESR1-mutated mBC. PATIENTS AND METHODS: In the open-label, phase II, ELAINE 2 trial (NCT04432454), women with ESR1-mutated, ER+/human epidermal growth factor receptor 2-negative (HER2-) mBC who progressed on prior therapies (including CDK4/6i) received lasofoxifene 5 mg/day and abemaciclib 150 mg b.i.d until disease progression/toxicity. The primary endpoint was safety/tolerability. Secondary endpoints included progression-free survival (PFS), clinical benefit rate (CBR), and objective response rate (ORR). RESULTS: Twenty-nine women (median age 60 years) participated; all but one were previously treated with a CDK4/6i (median duration 2 years). The lasofoxifene-abemaciclib combination was well tolerated with primarily grade 1/2 treatment-emergent adverse events (TEAEs), most commonly diarrhea, nausea, fatigue, and vomiting. One patient (with no prior CDK4/6i) discontinued treatment due to grade 2 diarrhea. No deaths occurred during the study. Median PFS was 56.0 weeks [95% confidence interval (CI) 31.9 weeks-not estimable; ∼13 months]; PFS rates at 6, 12, and 18 months were 76.1%, 56.1%, and 38.8%, respectively. CBR at 24 weeks was 65.5% (95% CI 47.3% to 80.1%). In 18 patients with measurable lesions, ORR was 55.6% (95% CI 33.7% to 75.4%). ESR1-mutant circulating tumor DNA (ctDNA) allele fraction decreased from baseline to week 4 in 21/26 (80.8%) patients. CONCLUSIONS: Lasofoxifene plus abemaciclib had an acceptable safety profile, was well tolerated, and exhibited meaningful antitumor activity in women with ESR1-mutated, ER+/HER2- mBC after disease progression on prior CDK4/6i. Observed decreases in ESR1-mutant ctDNA with lasofoxifene concordant with clinical response suggest target engagement. If the ELAINE 2 findings are confirmed in the initiated, phase III, ELAINE 3 trial, these data could be practice-changing and help address a critical unmet need.

Timing of smoking cessation treatment integrated into outpatient treatment with medications for opioid use disorder: Feasibility trial.

INTRODUCTION: Cigarette smoking rates among individuals with opioid use disorder (OUD) are notoriously high and may be improved by considering the timing of treatment integration for these two substances. The current study examined the feasibility of a method for assessing the timing of integrating smoking cessation pharmacotherapy within three different phases of outpatient treatment with medication for OUD (MOUD). METHODS: Seventy-four buprenorphine-maintained smokers were enrolled in a quasi-experimental study across three MOUD treatment phases: 0-90 (Phase 1), 91-365 (Phase 2), and > 365 days of MOUD treatment (Phase 3). During a 12-week varenicline-based intervention, the study assessed outcomes daily via text messages (cigarette smoking, varenicline adherence, side effects) or monthly at in-person visits (quit motivation and carbon monoxide levels). RESULTS: Thirty-five participants completed the study, with a lower retention rate in Phase 1 (37.5%) relative to Phases 2 (53.5%) or 3 (57.1%). A trend occurred for Phase 1 participants to report aversive side effects (e.g., abnormal dreams, gastrointestinal distress) on more study days. Among completers, adherence to text messaging and varenicline use was high and independent of MOUD treatment phase. Participants in all phases reported declines in cigarette smoking and increases in quit motivation over time; the study observed biochemically verified tobacco abstinence among only a few participants from Phases 2 or 3. CONCLUSIONS: This feasibility study demonstrates a method to evaluate the timing of treatment integration for cigarette smoking and MOUD. Method strengths include a study schedule that coincided with the MOUD clinic schedule and use of text messaging to encourage varenicline adherence and evaluate outcomes regularly.

Synovial sepsis of unknown origin in the adult Thoroughbred racehorse.

BACKGROUND: Synovial sepsis of unknown origin is a rare cause of lameness in the adult horse, and a haematogenous pathogenesis has been proposed in previous cases. OBJECTIVES: To describe the features and outcome of synovial sepsis of unknown origin in adult Thoroughbred racehorses. STUDY DESIGN: Retrospective case series. METHODS: Hospital records for admissions between 2005 and 2015 were reviewed to identify adult horses diagnosed with synovial sepsis of unknown origin. Presentation, clinicopathological, microbiological and diagnostic imaging findings were recorded. Treatment methods, surgical findings, complications and long-term outcome were evaluated. RESULTS: Eleven cases were identified over the study period. Diagnosis was established from clinical examination and clinicopathologic findings, which were comparable to other aetiologies of synovial sepsis. Affected structures included synovial joints, tendon sheaths and bursae. Concurrent osteochondritis dissecans or articular cartilage lesions were evident during arthroscopic surgery in three cases. Significant intrasynovial haemorrhage was not identified. Microbial culture of synovial fluid or synovial biopsy was positive in 6/11 of cases, with all isolates being Gram-positive cocci. Of the 6 positive microbial cultures, all isolates demonstrated in vitro sensitivity to a cephalosporin antimicrobial agent. A concurrent remote wound was present in a single case. No other potential origins of bacteraemia were identified. Treatment methods included endoscopic surgery, standing multineedle lavage, intravenous regional limb perfusion, intrasynovial medication and/or systemic antimicrobial administration. All horses survived to hospital discharge. For the 6/11 cases that raced following synovial sepsis, the median period for return to racing was 221 days. MAIN LIMITATIONS: A small study population, which was retrospectively reviewed. CONCLUSIONS: Synovial sepsis of unknown origin is rare in the adult Thoroughbred racehorse and can affect a range of synovial structures. A concurrent potential source of bacteraemia is rarely identified. With appropriate management, the prognosis to return to racing is fair.

A pilot investigation of the effect of electronic cigarettes on smoking behavior among opioid-dependent smokers.

INTRODUCTION: Compared to the general population, smoking rates are 2-4 times higher among individuals with opioid use disorders (OUDs). These smokers also have poor long-term cessation rates, even with pharmacotherapy or other interventions. Low success rates with traditional approaches may prompt smokers with OUDs to try more novel products like electronic cigarettes (ECIGs). This pilot study was designed to examine the feasibility, acceptability, and effect of ECIGs on smoking behavior among smokers with OUD. METHODS: Participants (N = 25) were daily smokers receiving buprenorphine/naloxone for OUD at an outpatient clinic. They were randomized to use a second-generation ECIG (0 or 18 ng/ml nicotine) ad libitum for two weeks while completing assessments via text messaging daily, and also via in-person visits at baseline, end of the two-week intervention, and a 4-week follow-up. RESULTS: Feasibility was evidenced by high enrollment (93.9%) and retention (70.9%) rates. ECIG adherence was relatively high as measured by self-report (80.6% active, 91.7% placebo), while the average volume of liquid used per week was low (~3 ml). Both ECIG doses produced reductions in self-reported cigarettes per day that were not supported by average carbon monoxide levels. Biologically-confirmed smoking abstinence was observed in 8% of participants. CONCLUSIONS: Preliminary results suggest that smokers with OUD are interested in using ECIGs, but their adherence may be less than ideal. Poor medication adherence rates are often observed in this disparate population, and future work should consider the use of other ECIG device types and a combination of methods to verify and quantify ECIG use.

How Well Does Intraoperative Audiologic Monitoring Predict Hearing Outcome During Middle Fossa Vestibular Schwannoma Resection?

OBJECTIVE: To evaluate the association between signal changes during intraoperative audiologic monitoring and postoperative audiometric outcome in patients undergoing vestibular schwannoma (VS) resection via middle cranial fossa (MCF) approach. STUDY DESIGN: Retrospective chart review. SETTING: Academic tertiary referral center. PATIENTS: One hundred twenty-six consecutive patients (mean age 48.6 yrs, range 16-67; mean tumor size 9.9 mm, range 1.8-18.9 mm) who underwent MCF VS resection. INTERVENTIONS: Intraoperative audiologic monitoring using auditory brainstem response (ABR) and direct cochlear nerve action potential (CNAP). MAIN OUTCOME MEASURES: Intraoperative ABR wave V and CNAP N1 amplitudes and postoperative pure-tone average (PTA) and word recognition score (WRS). RESULTS: On ABR, absent wave V amplitude was associated with an 81.1% increase and 82.3% decrease in postoperative PTA and WRS, respectively. On CNAP, decreased or absent N1 amplitude was associated with 47.3 and 100% increase, respectively, in postoperative PTA, and 45.3% and 100% decrease, respectively, in postoperative WRS. Receiver-operating curve analysis showed that ABR combined with CNAP using a Cueva electrode achieved the highest diagnostic accuracy in predicting postoperative hearing decline when measured by WRS class (sensitivity 83.3%, specificity 100%), and performed better compared with each modality alone. CONCLUSION: Intraoperative ABR wave V and CNAP amplitude changes are associated with changes in postoperative hearing, and dual modality monitoring was more diagnostic of postoperative hearing decline compared with each modality alone during MCF VS resection. Overall, intraoperative ABR and CNAP were more specific than sensitive for postoperative hearing decline.

Dynamic imaging with sialography combined with sialendoscopy to manage a foreign body in Stensen's duct.

OBJECTIVE: We describe sialography as a dynamic imaging modality useful in establishing the diagnosis and planning for treatment of a parotid gland ductal foreign body. METHODS: Chart and radiographic imaging review of a 75 year-old male who had obstructive sialadenitis symptoms two years after welding slag pierced the cheek skin and identified as a 'piece of steel stuck in his cheek'. RESULTS: Sialography was used to demonstrate a foreign body adjacent to the parotid gland to indicate its presence as a mobile element within the ductal system associated with marked pre-obstructive duct dilation. Sialendoscopy was used to successfully remove the foreign body. CONCLUSIONS: In selected cases, the management of obstructive sialadenitis can be improved with sialography in permitting dynamic imaging of salivary duct anatomy. Although ultrasound has evolved as a standard component of salivary gland assessment, sialography may complement imaging with ultrasound (or CT as in this case) to offer the highest acuity definition of the salivary ducts.

Technical Refinements and Outcomes of the Modified Anterior Septal Transplant.

IMPORTANCE: Severe anterior septal deviation and resultant nasal obstruction represent a difficult surgical task to correct. The goal of surgery is to straighten the anterior dorsal and caudal struts, while maintaining nasal tip and midvault support. This study presents a novel extracorporeal septoplasty technique to straighten the crooked anterior septum. OBJECTIVE: To describe the novel anterior septal transplant technique, which consists of complete resection of the caudal septum and reconstruction with extended spreader grafts and a columellar strut, without a separate caudal septal replacement graft. DESIGN, SETTING, AND PARTICIPANTS: This study was a retrospective case series at a tertiary academic referral center. Participants were sequential adult patients undergoing anterior septal transplant from January 1, 2008, to December 31, 2015. MAIN OUTCOMES AND MEASURES: Patient-reported nasal obstruction using Nasal Obstruction Symptom Evaluation (NOSE) scores and objective photographic analysis. Nasal tip deviation, projection, and rotation were measured. Preoperative and postoperative outcomes were compared. Complications are reported. RESULTS: Seventy-one patients (mean age, 46 years [age range, 16-72 years]; 48 [67.6%] female and 23 [32.4%] male) were included in the case series. Postoperative NOSE scores (mean [SD], 24.00 [24.58]) were significantly better than preoperative NOSE scores (mean [SD], 72.25 [14.55]) (P < .001). A separate cohort of 32 patients (mean age, 42 years [age range, 13-72 years]; 23 [71.9%] female and 9 [28.1%] male) had photographs available for analysis. In the frontal view, nasal deviation improved from a mean (SD) of 2.9 (2.0) degrees before surgery to a mean (SD) of 1.4 (1.7) degrees after surgery (P = .004). In the base view, the deviation was corrected from a mean (SD) of 4.9 (2.8) degrees to a mean (SD) of 1.7 (1.2) degrees (P < .001). Tip rotation and projection were unchanged after surgery. Four patients had mild dorsal irregularities after surgery. CONCLUSIONS AND RELEVANCE: Anterior septal transplant by the described technique is a safe and effective treatment option for severe anterior septal deviation. LEVEL OF EVIDENCE: 4.

Assessing the delivery of alcohol screening and brief intervention in sexual health clinics in the north east of England.

BACKGROUND: Risky drinking is associated with risky sexual experiences, however the relationship between alcohol and sex is complex. The aim of the study was to assess the feasibility of delivering alcohol screening and brief interventions in genitourinary medicine (GUM) clinics. The objectives were to; understand the levels of alcohol use amongst patients; report on the number of alcohol interventions delivered; and to analyse the relationship between alcohol use with demographic data as well as diagnosed sexually transmitted infections (STIs) to see if there were any associations. METHODS: All new patients attending GUM between April 2012 and March 2013 self-completed the Alcohol Use Disorder Identification Test (AUDIT) prior to their clinical consultation. Where appropriate (scoring 8+ on AUDIT) the clinician would deliver up to 2-3 min of alcohol brief intervention. Descriptive statistics, t-tests, ANOVA and logistic regression were carried out as appropriate. RESULTS: AUDIT scores were available for 90% of all new patients (3058/3390) with an average mean score of 7.75. Of those who drank alcohol, 44% were categorised as being AUDIT positive, including 2% who had a score indicative of probable alcohol dependence (20+). 55 % (n = 638) of patients who screened positive on the AUDIT received a brief intervention whilst 24% (n = 674) of drinkers were diagnosed with a STI. Logistic regression modelling revealed that males, younger age groups and those of 'white' ethnicity were more likely to score positive on AUDIT. Patients classified as non-students, living in deprivation quintiles one to four and categorised as probable alcohol dependence on the AUDIT were more likely to be diagnosed with an STI. CONCLUSION: It is possible to embed alcohol screening into routine practice within sexual health services however further work is required to embed brief interventions particularly amongst increasing risk drinkers. If resources are limited, services may consider more targeted rather than universal alcohol screening to specific population groups. The study was undertaken in one GUM service in the North East of England and therefore findings may not be generalizable. The study did not assess efficacy of alcohol brief intervention in this setting.

Infectious disease models in zebrafish.

In recent years, the zebrafish (Danio rerio) has developed as an important alternative to mammalian models for the study of hostpathogen interactions. Because they lack a functional adaptive immune response during the first 4-6weeks of development, zebrafish rely upon innate immune responses to protect against injuries and infections. During this early period of development, it is possible to isolate and study mechanisms of infection and inflammation arising from the innate immune response without the complications presented by the adaptive immune response. Zebrafish possess several inherent characteristics that make them an attractive option to study hostpathogen interactions, including extensive sequence and functional conservation with the human genome, optical clarity in larvae that facilitates the high-resolution visualization of host cell-microbe interactions, a fully sequenced and annotated genome, robust forward and reverse genetic tools and techniques (e.g., CRISPR-Cas9 and TALENs), and amenability to chemical studies and screens. Here, we describe methods for studying hostpathogen interactions both through systemic infections and through localized infections that allow analysis of host cell response, migration patterns, and behavior. Each of the methods described can be modified for use in downstream applications that include ecotoxicant studies and chemical screens.

Proton therapy in paediatric oncology: an Irish perspective.

BACKGROUND: Proton therapy (PT) is a radiotherapy treatment modality that uses protons, rather than conventional photons. PT is often used in paediatric oncology due to its reported capability to reduce acute and late adverse treatment effects. As PT is unavailable in Ireland, patients are referred abroad for treatment. AIMS: To: (1) produce a descriptive study of Irish children referred abroad for PT, and (2) discuss the case for PT in general. METHODS: A retrospective review of all children referred for PT before October 2015 was performed. Information was gathered regarding demographics, diagnosis, referral timeline, adverse effects attributable to PT, current status and cost. A review of the relevant literature was performed. RESULTS: Seventeen children treated in Ireland have been referred abroad for PT. The largest number was in the 0-4 year old group. At initial diagnosis the median age was 4.8 years. The average cost per child was €37,312. Two patients suffered disease relapse. Four have encountered PT-related adverse effects. CONCLUSION: Despite the fact that >100,000 patients worldwide have been treated with PT, the level of published evidence to support superiority over conventional treatment remains low. It is debated that randomised control trials in this area would be inconsistent with the principle of clinical equipoise. In contrast, there is a call for level 1 evidence to justify drastic changes in patient care, particularly in light of recent reports of unexpected toxicities. In time, careful evaluation, follow-up and clinical trials will likely support the preferential use of PT in children.

ANG1005 for breast cancer brain metastases: correlation between 18F-FLT-PET after first cycle and MRI in response assessment.

PURPOSE: Improved therapies and imaging modalities are needed for the treatment of breast cancer brain metastases (BCBM). ANG1005 is a drug conjugate consisting of paclitaxel covalently linked to Angiopep-2, designed to cross the blood-brain barrier. We conducted a biomarker substudy to evaluate 18F-FLT-PET for response assessment. METHODS: Ten patients with measurable BCBM received ANG1005 at a dose of 550 mg/m2 IV every 21 days. Before and after cycle 1, patients underwent PET imaging with 18F-FLT, a thymidine analog, retention of which reflects cellular proliferation, for comparison with gadolinium-contrast magnetic resonance imaging (Gd-MRI) in brain metastases detection and response assessment. A 20 % change in uptake after one cycle of ANG1005 was deemed significant. RESULTS: Thirty-two target and twenty non-target metastatic brain lesions were analyzed. The median tumor reduction by MRI after cycle 1 was -17.5 % (n = 10 patients, lower, upper quartiles: -25.5, -4.8 %) in target lesion size compared with baseline. Fifteen of twenty-nine target lesions (52 %) and 12/20 nontarget lesions (60 %) showed a ≥20 % decrease post-therapy in FLT-PET SUV change (odds ratio 0.71, 95 % CI: 0.19, 2.61). The median percentage change in SUVmax was -20.9 % (n = 29 lesions; lower, upper quartiles: -42.4, 2.0 %), and the median percentage change in SUV80 was also -20.9 % (n = 29; lower, upper quartiles: -49.0, 0.0 %). Two patients had confirmed partial responses by PET and MRI lasting 6 and 18 cycles, respectively. Seven patients had stable disease, receiving a median of six cycles. CONCLUSIONS: ANG1005 warrants further study in BCBM. Results demonstrated a moderately strong association between MRI and 18F-FLT-PET imaging.

The lived experience of fatigue in children and adolescents with cancer: a systematic review.

PURPOSE: Objectives of this systematic review were to summarize how fatigue has been described from the perspective of children and adolescents with cancer, the impact of fatigue on quality of life, and child reported contributing factors and potential alleviators of fatigue. METHODS: We conducted electronic searches of Ovid Medline, EMBASE, PsycInfo, Science Citation, Social Science Citation (Web of Science), and CINAHL. We included studies of children and adolescents with cancer in which the experience of fatigue was described by the child/adolescent. The search was restricted to publications in English. Themes were summarized. RESULTS: Eleven studies were represented in 18 publications. Ages of included children ranged from 6 to 19 years. Majority of studies used semi-structured interviews to elicit participant's perceptions of fatigue. Terms used to describe fatigue included the following: tiredness, weary, loss of strength, dizziness, feeling drained, feeling drowsy, lacking motivation, exhaustion, and feeling emotional. Impact of fatigue related to not being able to participate in regular activities; needing to sleep or rest more; and impact on psychosocial health. Perceived alleviators of fatigue included exercise, distraction, rest, eating, and drinking. CONCLUSIONS: Fatigue is impactful from the perspective of children and adolescents. Future research should focus on prospective exploration of the impact of fatigue on pediatric cancer patients and identifying approaches to reduce fatigue.

Multiplex PCB-based electrochemical detection of cancer biomarkers using MLPA-barcode approach.

Asymmetric multiplex ligation-dependent probe amplification (MLPA) was developed for the amplification of seven breast cancer related mRNA markers and the MLPA products were electrochemically detected via hybridization. Seven breast cancer genetic markers were amplified by means of the MLPA reaction, which allows for multiplex amplification of multiple targets with a single primer pair. Novel synthetic MLPA probes were designed to include a unique barcode sequence in each amplified gene. Capture probes complementary to each of the barcode sequences were immobilized on each electrode of a low-cost electrode microarray manufactured on standard printed circuit board (PCB) substrates. The functionalised electrodes were exposed to the single-stranded MLPA products and following hybridization, a horseradish peroxidase (HRP)-labelled DNA secondary probe complementary to the amplified strand completed the genocomplex, which was electrochemically detected following substrate addition. The electrode arrays fabricated using PCB technology exhibited an excellent electrochemical performance, equivalent to planar photolithographically-fabricated gold electrodes, but at a vastly reduced cost (>50 times lower per array). The optimised system was demonstrated to be highly specific with negligible cross-reactivity allowing the simultaneous detection of the seven mRNA markers, with limits of detections as low as 25pM. This approach provides a novel strategy for the genetic profiling of tumour cells via integrated "amplification-to-detection".

Management of Potential Long-Term Toxicities in Breast Cancer Patients.

Breast cancer is the most common non-cutaneous malignancy among women, and there are over 3 million breast cancer survivors living in the United States today. Excellent cure rates with modern therapies are associated with substantial toxicities for many women; it is important that health care providers attend to the resulting symptoms and issues to optimize quality of life in this population. In this article, we review management options for potential long term toxicities in breast cancer survivors, with a particular focus on bone health, fertility preservation, premature menopause, cardiac dysfunction, and cognitive impairment.

Ligand-Specific Transcriptional Mechanisms Underlie Aryl Hydrocarbon Receptor-Mediated Developmental Toxicity of Oxygenated PAHs.

Polycyclic aromatic hydrocarbons (PAHs) are priority environmental contaminants that exhibit mutagenic, carcinogenic, proinflammatory, and teratogenic properties. Oxygen-substituted PAHs (OPAHs) are formed during combustion processes and via phototoxidation and biological degradation of parent (unsubstituted) PAHs. Despite their prevalence both in contaminated industrial sites and in urban air, OPAH mechanisms of action in biological systems are relatively understudied. Like parent PAHs, OPAHs exert structure-dependent mutagenic activities and activation of the aryl hydrocarbon receptor (AHR) and cytochrome p450 metabolic pathway. Four-ring OPAHs 1,9-benz-10-anthrone (BEZO) and benz(a)anthracene-7,12-dione (7,12-B[a]AQ) cause morphological aberrations and induce markers of oxidative stress in developing zebrafish with similar potency, but only 7,12-B[a]AQ induces robust Cyp1a protein expression. We investigated the role of the AHR in mediating the toxicity of BEZO and 7,12-B[a]AQ, and found that knockdown of AHR2 rescued developmental effects caused by both compounds. Using RNA-seq and molecular docking, we identified transcriptional responses that precede developmental toxicity induced via differential interaction with AHR2. Redox-homeostasis genes were affected similarly by these OPAHs, while 7,12-B[a]AQ preferentially activated phase 1 metabolism and BEZO uniquely decreased visual system genes. Analysis of biological functions and upstream regulators suggests that BEZO is a weak AHR agonist, but interacts with other transcriptional regulators to cause developmental toxicity in an AHR-dependent manner. Identifying ligand-dependent AHR interactions and signaling pathways is essential for understanding toxicity of this class of environmentally relevant compounds.

Neutralization of mitochondrial superoxide by superoxide dismutase 2 promotes bacterial clearance and regulates phagocyte numbers in zebrafish.

Mitochondria are known primarily as the location of the electron transport chain and energy production in cells. More recently, mitochondria have been shown to be signaling centers for apoptosis and inflammation. Reactive oxygen species (ROS) generated as by-products of the electron transport chain within mitochondria significantly impact cellular signaling pathways. Because of the toxic nature of ROS, mitochondria possess an antioxidant enzyme, superoxide dismutase 2 (SOD2), to neutralize ROS. If mitochondrial antioxidant enzymes are overwhelmed during severe infections, mitochondrial dysfunction can occur and lead to multiorgan failure or death. Pseudomonas aeruginosa is an opportunistic pathogen that can infect immunocompromised patients. Infochemicals and exotoxins associated with P. aeruginosa are capable of causing mitochondrial dysfunction. In this work, we describe the roles of SOD2 and mitochondrial ROS regulation in the zebrafish innate immune response to P. aeruginosa infection. sod2 is upregulated in mammalian macrophages and neutrophils in response to lipopolysaccharide in vitro, and sod2 knockdown in zebrafish results in an increased bacterial burden. Further investigation revealed that phagocyte numbers are compromised in Sod2-deficient zebrafish. Addition of the mitochondrion-targeted ROS-scavenging chemical MitoTEMPO rescues neutrophil numbers and reduces the bacterial burden in Sod2-deficient zebrafish. Our work highlights the importance of mitochondrial ROS regulation by SOD2 in the context of innate immunity and supports the use of mitochondrion-targeted ROS scavengers as potential adjuvant therapies during severe infections.