Biodegradation of endocrine disrupting chemicals benzyl butyl phthalate and dimethyl phthalate by Bacillus marisflavi RR014

AIM

The objectives of the present study were to explore the benzyl butyl phthalate (BBP) and dimethyl phthalate (DMP) degradation potential of Bacillus marisflavi RR014 isolated from the tap water of public toilet and also to optimize the phthalates degradation process using response surface methodology.

METHODS AND RESULTS

The minimal salt medium was used for the biodegradation analysis of phthalates. The quantification of phthalates and their intermediate metabolites identification were done by using UHPLC and LC-MS/MS respectively. The results revealed that B. marisflavi RR014 is capable of degrading both the phthalates under varying pH, temperature and salinity conditions. The formation of phthalic acid from the breakdown of BBP and DMP (500 mg l^-1 ) in the medium was observed after 24 h. After 72 h, 61% of BBP and 98·9% of DMP in the medium was degraded as monitored by UHPLC. The identification of intermediate metabolites by LC-MS/MS revealed that hydrolysis of BBP and DMP produces phthalic acid.

CONCLUSIONS

The degradation rate of both the phthalates was increased as the parameters increased up to an optimum level. The three environmental factors (pH, temperature and salt concentration) strongly affect the rate of degradation of both the phthalates. The maximum degradation rate for both the phthalates was achieved at pH 7, temperature 35°C and salt concentration of 1% as observed from the central composite experimental design.

SIGNIFICANCE AND IMPACT OF THE STUDY

It is the first report on the phthalates biodegradation potential of B. marisflavi RR014 isolated from the tap water of public toilet. The bacterium is capable of degrading BBP and DMP under varying pH, temperature and salinity, therefore, ideal to treat the phthalate contaminated environments.

Association of Reperfusion After Thrombolysis With Clinical Outcome Across the 4.5- to 9-Hours and Wake-up Stroke Time Window: A Meta-Analysis of the EXTEND and EPITHET Randomized Clinical Trials

Importance

Intravenous alteplase reduces disability after ischemic stroke in patients 4.5 to 9 hours after onset and with wake-up onset stroke selected using perfusion imaging mismatch. However, whether the benefit is consistent across the 4.5- to 6-hours, 6- to 9-hours, and wake-up stroke epochs is uncertain.

Objective

To examine the association of reperfusion with reduced disability, including by onset-to-randomization time strata in the Extending the Time for Thrombolysis in Emergency Neurological Deficits (EXTEND) and Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) randomized clinical trials.

Design, Setting, and Participants

Individual patient meta-analysis of randomized clinical trials performed from August 2001 to June 2018 with 3-month follow-up. Patients had acute ischemic stroke with 4.5-to 9-hours poststroke onset or with wake-up stroke were randomized to alteplase or placebo after perfusion mismatch imaging. Analysis began July 2019 and ended May 2020.

Exposures

Reperfusion was defined as more than 90% reduction in time to maximum of more than 6 seconds' lesion volume at 24- to 72-hour follow-up.

Main Outcomes and Measures

Ordinal logistic regression adjusted for baseline age and National Institutes of Health Stroke Scale score was used to analyze functional improvement in day 90 modified Rankin Scale score overall, including a reperfusion × time-to-randomization multiplicative interaction term, and in the 4.5- to 6-hours, 6- to 9-hours, and wake-up time strata. Symptomatic hemorrhage was defined as large parenchymal hematoma with a National Institutes of Health Stroke Scale score increase of 4 points or more.

Results

Reperfusion was assessable in 270 of 295 patients (92%), 68 of 133 (51%) in the alteplase group, and 38 of 137 (28%) in the placebo reperfused group (P < .001). The median (interquartile range) age was 76 (66-81) years in the reperfusion group vs 74 (64.5-81.0) years in the group with no reperfusion. The median (interquartile range) baseline National Institutes of Health Stroke Scale score was 10 (7-15) in the reperfusion group vs 12 (8.0-17.5) in the no reperfusion group. Overall, reperfusion was associated with improved functional outcome (common odds ratio, 7.7; 95% CI, 4.6-12.8; P < .001). Reperfusion was associated with significantly improved functional outcome in each of the 4.5- to 6-hours, 6- to 9-hours, and wake-up time strata, with no evidence of association between time to randomization and beneficial effect of reperfusion (P = .63). Symptomatic hemorrhage, assessed in all 294 patients, occurred in 3 of 51 (5.9%) in the 4.5- to 6-hours group, 2 of 28 (7.1%) in the 6- to 9-hours group, and 4 of 73 (5.5%) in the wake-up stroke in patients treated with alteplase (Fisher P = .91).

Conclusions and Relevance

Strong benefits of reperfusion in all time strata without differential risk in symptomatic hemorrhage support the consistent treatment effect of alteplase in perfusion mismatch-selected patients throughout the 4.5- to 9-hours and wake-up stroke time window.

Tenecteplase vs Alteplase Before Endovascular Therapy in Basilar Artery Occlusion

OBJECTIVE

To investigate the efficacy of tenecteplase (TNK), a genetically modified variant of alteplase with greater fibrin specificity and longer half-life than alteplase, prior to endovascular thrombectomy (EVT) in patients with basilar artery occlusion (BAO).

METHODS

To determine whether TNK is associated with better reperfusion rates than alteplase prior to EVT in BAO, clinical and procedural data of consecutive patients with BAO from the Basilar Artery Treatment and Management (BATMAN) registry and the Tenecteplase vs Alteplase before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK) trial were retrospectively analyzed. Reperfusion >50% or absence of retrievable thrombus at the time of the initial angiogram was evaluated.

RESULTS

We included 110 patients with BAO treated with IV thrombolysis prior to EVT (mean age 69 [SD 14] years; median NIH Stroke Scale score 16 [interquartile range (IQR) 7-32]). Nineteen patients were thrombolysed with TNK (0.25 mg/kg or 0.40 mg/kg) and 91 with alteplase (0.9 mg/kg). Reperfusion >50% occurred in 26% (n = 5/19) of patients thrombolysed with TNK vs 7% (n = 6/91) thrombolysed with alteplase (risk ratio 4.0, 95% confidence interval 1.3-12; p = 0.02), despite shorter thrombolysis to arterial puncture time in the TNK-treated patients (48 [IQR 40-71] minutes) vs alteplase-treated patients (110 [IQR 51-185] minutes; p = 0.004). No difference in symptomatic intracranial hemorrhage was observed (0/19 [0%] TNK, 1/91 [1%] alteplase; p = 0.9).

CONCLUSIONS

TNK may be associated with an increased rate of reperfusion in comparison with alteplase before EVT in BAO. Randomized controlled trials to compare TNK with alteplase in patients with BAO are warranted.

CLINICALTRIALSGOV IDENTIFIERS

NCT02388061 and NCT03340493.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that TNK leads to higher reperfusion rates in comparison with alteplase prior to EVT in patients with BAO.

Diabetes and COVID-19: a major challenge in pandemic period?

OBJECTIVE

Diabetes is a lifestyle disease and it has become an epidemic worldwide in recent decades. In the ongoing COVID-19 pandemic situation, diabetes has become a serious health concern since large numbers of patients are vulnerable to die from the virus. Thus, diabetic patients affected by COVID-19 cause a major health crisis now. Reports show that large occurrence of diabetes makes it a serious comorbidity in COVID-19 patients.

MATERIALS AND METHODS

It is crucial to understand how COVID-19 affects diabetes patients. This paper has reviewed published literature extensively to understand the pattern, importance, care, and medication.

RESULTS

This review summarizes the association between COVID-19 and diabetes in terms of susceptibility for pneumonia and other diseases. It also discusses the harshness of COVID-19 with diabetes populations and immunological impacts. It further adds the ACE2 receptor role in diabetes with COVID-19 patients.

CONCLUSIONS

Finally, this paper illustrates different types of diabetes management techniques, such as blood glucose management, self-management, mental health management, and therapeutic management. It also summarizes the current knowledge about diabetic patients with COVID-19 to fight this pandemic.

Tranexamic acid in patients with intracerebral haemorrhage (STOP-AUST): a multicentre, randomised, placebo-controlled, phase 2 trial

BACKGROUND

Despite intracerebral haemorrhage causing 5% of deaths worldwide, few evidence-based therapeutic strategies other than stroke unit care exist. Tranexamic acid decreases haemorrhage in conditions such as acute trauma and menorrhoea. We aimed to assess whether tranexamic acid reduces intracerebral haemorrhage growth in patients with acute intracerebral haemorrhage.

METHODS

We did a prospective, double-blind, randomised, placebo-controlled, investigator-led, phase 2 trial at 13 stroke centres in Australia, Finland, and Taiwan. Patients were eligible if they were aged 18 years or older, had an acute intracerebral haemorrhage fulfilling clinical criteria (eg, Glasgow Coma Scale score of >7, intracerebral haemorrhage volume <70 mL, no identified or suspected secondary cause of intracerebral haemorrhage, no thrombotic events within the previous 12 months, no planned surgery in the next 24 h, and no use of anticoagulation), had contrast extravasation on CT angiography (the so-called spot sign), and were treatable within 4·5 h of symptom onset and within 1 h of CT angiography. Patients were randomly assigned (1:1) to receive either 1 g of intravenous tranexamic acid over 10 min followed by 1 g over 8 h or matching placebo, started within 4·5 h of symptom onset. Randomisation was done using a centralised web-based procedure with randomly permuted blocks of varying size. All patients, investigators, and staff involved in patient management were masked to treatment. The primary outcome was intracerebral haemorrhage growth (>33% relative or >6 mL absolute) at 24 h. The primary and safety analyses were done in the intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT01702636).

FINDINGS

Between March 1, 2013, and Aug 13, 2019, we enrolled and randomly assigned 100 participants to the tranexamic acid group (n=50) or the placebo group (n=50). Median age was 71 years (IQR 57-79) and median intracerebral haemorrhage volume was 14·6 mL (7·9-32·7) at baseline. The primary outcome was not different between the two groups: 26 (52%) patients in the placebo group and 22 (44%) in the tranexamic acid group had intracerebral haemorrhage growth (odds ratio [OR] 0·72 [95% CI 0·32-1·59], p=0·41). There was no evidence of a difference in the proportions of patients who died or had thromboembolic complications between the groups: eight (16%) in the placebo group vs 13 (26%) in the tranexamic acid group died and two (4%) vs one (2%) had thromboembolic complications. None of the deaths was considered related to study medication.

INTERPRETATION

Our study does not provide evidence that tranexamic acid prevents intracerebral haemorrhage growth, although the treatment was safe with no increase in thromboembolic complications. Larger trials of tranexamic acid, with simpler recruitment methods and an earlier treatment window, are justified.

FUNDING

National Health and Medical Research Council, Royal Melbourne Hospital Foundation.

Energy consumption, FDI, and urbanization linkage in coastal Mediterranean countries: re-assessing the pollution haven hypothesis

Foreign direct investment (FDI) and the consumption of non-renewable energy have been on the increase in the coastal Mediterranean countries (CMCs) over the last few decades. Both trigger growth, but the environmental impact could be far-reaching as environmental distortions are mainly human-induced. This study examines the environmental issues facing CMCs. Specifically, we investigate whether the pollution haven hypothesis holds for CMCs. We employ a quantile panel data analysis for CMCs to account for heterogeneity and distributional effects of socioeconomic factors. The result reveals that the influence of FDI on environmental degradation is a function of the indicators utilized and also depends on the initial levels of environmental degradation. The results suggest that the pollution haven hypothesis does not hold for CMCs. However, we also find that energy consumption significantly increases environmental degradation for all indicators and across the observed quantiles. The effects of economic growth and urbanization on the environment were mixed for the different indicators and across quantiles. We recommend that it is pertinent for CMCs to limit their "dirty" energy sources and substitute them with renewables to promote environmental sustainability.

Recombinant production, bioconjugation and membrane binding studies ofPn3a, a selective NaV1.7 inhibitor

Chronic pain is a common and often debilitating condition. Existing treatments are either inefficacious or associated with a wide range of side effects. The progress on developing safer and more effective analgesics has been slow, in large part due to our limited understanding of the physiological mechanisms underlying pain in different diseases. Generation and propagation of action potentials is a central component of pain sensation and voltage-gated sodium channels (Na_Vs) play a critical role in this process. In particular, the Na_V subtype 1.7, has emerged as a promising universal target for the treatment of pain. Recently, a spider venom peptide, μ-TRTX-Pn3a, was found to be a highly selective inhibitor of Na_V1.7. Here, we report the first recombinant expression method for Pn3a in a bacterial host, which provides an inexpensive route to production. Furthermore, we have developed a method for bio-conjugation of our recombinantly produced Pn3a via sortase A-mediated ligation, providing avenues for further pre-clinical development. We demonstrate how heterologous expression in bacteria enables facile isotope labelling of Pn3a, which allowed us to study the membrane binding properties of the peptide by high-resolution solution-state nuclear magnetic resonance (NMR) spectroscopy using a recently developed lipid nanodisc system. The heteronuclear NMR data indicate that the C-terminal region of the peptide undergoes a conformational change upon lipid binding. The membrane binding properties of Pn3a are further validated using isothermal titration calorimetry (ITC), which revealed that Pn3a binds to zwitterionic planar lipid bilayers with thermodynamics that are largely driven by enthalpic contributions.

Renewable energy, urbanization, and ecological footprint linkage in CIVETS

Emerging economies are mostly plague by a massive consumption of non-renewable energy amidst an ever inceasing urbanization rate with little or no attention to the quality of the environmental. As such, this paper investigates the relationship between renewable energy, urbanization, economic growth, trade openness, and ecological footprint in CIVETS countries, namely, Colombia, Indonesia, Vietnam, Egypt, Turkey, and South Africa. The study employs augmented mean group estimator, panel cointegration, and causality tests. The findings reveal that renewable energy improves environmental quality, and trade is not particularly harmful to the environment. However, non-renewable energy consumption and urbanization are the chief contributors to environmental degradation in the CIVETS countries. Economic expansion mitigates environmental deterioration in Colombia, South Africa, and Turkey, but contributes to pollution in Egypt, Indonesia, and Vietnam. Finally, the causality test suggests that urbanization drives environmental degradation. Policy directions are discussed.

Ictal autonomic activity recorded via wearable-sensors plus machine learning can discriminate epileptic and psychogenic nonepileptic seizures

Differentiating epileptic seizures (ES) and psychogenic nonepileptic seizures (PNES) is commonly based on electroencephalogram and concurrent video recordings (vEEG). Here, we demonstrate that these two types of seizures can be discriminated based on signals related to autonomic nervous system activity recorded via wearable sensors. We used Empatica E4 Wristband sensors worn on both arms in vEEG confirmed seizures, and machine learning methods to train classifiers, specifically, extreme gradient boosting (XGBoost). Classification performance achieved a predictive accuracy of 78 ± 1.5% on previously unseen data for whether a seizure was epileptic or psychogenic, which is 6 standard deviations above the baseline of 68% accuracy. Our dataset contained altogether 35 seizures from 18 patients out of which 8 patients had 13 convulsive seizures. Prediction of seizure type was based on simple features derived from the segments of autonomic activity measurements (electrodermal activity, body temperature, blood volume pulse, and heart rate) and forearm acceleration. Features related to heart rate and electrodermal activity were ranked as the top predictors in XGBoost classifiers. We found that patients with PNES had a higher ictal heart rate and electrodermal activity than patients with ES. In contrast to existing published studies of mainly convulsive seizures, our classifier focuses on autonomic signals to differentiate convulsive or nonconvulsive semiology ES from PNES. Our results show that autonomic activity recorded via wearable sensors provides promising signals for detection and discrimination of psychogenic and epileptic seizures, but more work is necessary to improve the predictive power of the model.

SARS-CoV-2 causing pneumonia-associated respiratory disorder (COVID-19): diagnostic and proposed therapeutic options

SARS-CoV-2 is responsible for the outbreak of severe respiratory illness (COVID-19) in Wuhan City, China and is now spreading rapidly throughout the world. The prompt outbreak of COVID-19 and its quick spread without any controllable measure defines the severity of the situation. In this crisis, a collective pool of knowledge about the advancement of clinical diagnostic and management for COVID-19 is a prerequisite. Here, we summarize all the available updates on the multidisciplinary approaches for the advancement of diagnosis and proposed therapeutic strategies for COVID-19. Moreover, the review discusses different aspects of the COVID-19, including its epidemiology; incubation period; the general clinical features of patients; the clinical features of intensive care unit (ICU) patients; SARS-CoV-2 infection in the presence of co-morbid diseases and the clinical features of pediatric patients infected with the SARS-CoV-2. Advances in various diagnostic approaches, such as the use of real-time polymerase chain reaction (RT-PCR), chest radiography, and computed tomography (CT) imaging; and other modern diagnostic methods, for this infection have been highlighted. However, due to the unavailability of adequate evidence, presently there are no officially approved drugs or vaccines available against SARS-CoV-2. Additionally, we have discussed various therapeutic strategies for COVID-19 under different categories, like the possible treatment plans with drug (antiviral drugs and anti-cytokines) therapy for disease prevention. Lastly, potentials candidates for the vaccines against SARS-CoV-2 infection have been described. Collectively, the review provides an overview of the SARS-CoV-2 infection outbreak along with the recent advancements and strategies for diagnosis and therapy of COVID-19.

Effect of Intravenous Tenecteplase Dose on Cerebral Reperfusion Before Thrombectomy in Patients With Large Vessel Occlusion Ischemic Stroke: The EXTEND-IA TNK Part 2 Randomized Clinical Trial

IMPORTANCE

Intravenous thrombolysis with tenecteplase improves reperfusion prior to endovascular thrombectomy for ischemic stroke compared with alteplase.

OBJECTIVE

To determine whether 0.40 mg/kg of tenecteplase safely improves reperfusion before endovascular thrombectomy vs 0.25 mg/kg of tenecteplase in patients with large vessel occlusion ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial at 27 hospitals in Australia and 1 in New Zealand using open-label treatment and blinded assessment of radiological and clinical outcomes. Patients were enrolled from December 2017 to July 2019 with follow-up until October 2019. Adult patients (N = 300) with ischemic stroke due to occlusion of the intracranial internal carotid, \basilar, or middle cerebral artery were included less than 4.5 hours after symptom onset using standard intravenous thrombolysis eligibility criteria.

INTERVENTIONS

Open-label tenecteplase at 0.40 mg/kg (maximum, 40 mg; n = 150) or 0.25 mg/kg (maximum, 25 mg; n = 150) given as a bolus before endovascular thrombectomy.

MAIN OUTCOMES AND MEASURES

The primary outcome was reperfusion of greater than 50% of the involved ischemic territory prior to thrombectomy, assessed by consensus of 2 blinded neuroradiologists. Prespecified secondary outcomes were level of disability at day 90 (modified Rankin Scale [mRS] score; range, 0-6); mRS score of 0 to 1 (freedom from disability) or no change from baseline at 90 days; mRS score of 0 to 2 (functional independence) or no change from baseline at 90 days; substantial neurological improvement at 3 days; symptomatic intracranial hemorrhage within 36 hours; and all-cause death.

RESULTS

All 300 patients who were randomized (mean age, 72.7 years; 141 [47%] women) completed the trial. The number of participants with greater than 50% reperfusion of the previously occluded vascular territory was 29 of 150 (19.3%) in the 0.40 mg/kg group vs 29 of 150 (19.3%) in the 0.25 mg/kg group (unadjusted risk difference, 0.0% [95% CI, -8.9% to -8.9%]; adjusted risk ratio, 1.03 [95% CI, 0.66-1.61]; P = .89). Among the 6 secondary outcomes, there were no significant differences in any of the 4 functional outcomes between the 0.40 mg/kg and 0.25 mg/kg groups nor in all-cause deaths (26 [17%] vs 22 [15%]; unadjusted risk difference, 2.7% [95% CI, -5.6% to 11.0%]) or symptomatic intracranial hemorrhage (7 [4.7%] vs 2 [1.3%]; unadjusted risk difference, 3.3% [95% CI, -0.5% to 7.2%]).

CONCLUSIONS AND RELEVANCE

Among patients with large vessel occlusion ischemic stroke, a dose of 0.40 mg/kg, compared with 0.25 mg/kg, of tenecteplase did not significantly improve cerebral reperfusion prior to endovascular thrombectomy. The findings suggest that the 0.40-mg/kg dose of tenecteplase does not confer an advantage over the 0.25-mg/kg dose in patients with large vessel occlusion ischemic stroke in whom endovascular thrombectomy is planned.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03340493.

Gradient of Tissue Injury after Stroke: Rethinking the Infarct versus Noninfarcted Dichotomy

AIM

To evaluate the degree of variability in microstructural injury within and adjacent to regions identified as infarcted tissue using diffusion tensor imaging (DTI).

METHODS

In this prospective longitudinal study, 18 patients presenting within 12 h of anterior circulation acute ischemic stroke who underwent CT perfusion (CTP) at baseline followed by fluid-attenuated inversion recovery (FLAIR) and DTI 1-month were analyzed. Four regions of interest (ROI) corresponding to the severity of hypoperfusion on CTP within and beyond the radiological infarct lesion defined on FLAIR were segmented. Fractional anisotropy (FA) and mean diffusivity (MD) were quantified for each ROI and compared to a mirror homologue in the contralateral hemisphere. Ipsilateral to contralateral FA and MD ratios were compared across ROIs.

RESULTS

Lower FA and higher MD values were observed within both the infarct lesion and the peri-infarct tissue compared with their homologous contralateral brain regions (all comparisons p ≤ 0.01). No difference was observed in FA and MD between remote nonhypoperfused tissue and its contralateral homologous region (FA p = 0.42, MD p ≥ 0.99). The magnitude of asymmetry (ipsilateral/contralateral ratios) of FA and MD was greater with increasing severity of hypoperfusion in a dose-response pattern. Asymmetry greatest in the area of infarction with severe hypoperfusion, followed by infarction with moderate hypoperfusion, the peri-infarct hypoperfused tissue, and lastly the remote nonhypoperfused normal tissue (median on clustered quantile regression p ≤ 0.01).

CONCLUSION

A gradient of microstructural injury corresponding to the severity of ischemic insult is present within and beyond conventionally defined infarct boundaries. The traditional dichotomized notion of infarcted versus noninfarcted tissue widely adopted in clinical research and in practice warrants reexamination.

Abstract 100: Reperfusion Improves Clinical Outcome Across the 4.5-9h and Wake-Up Stroke Time Continuum in EXTEND and EPITHET

Introduction: Intravenous alteplase reduces disability after ischemic stroke in patients 4.5-9h after onset and with wake-up onset stroke who have favorable perfusion imaging. We examined the benefit of reperfusion in reducing disability, including by onset to randomization time strata in the EXTEND and EPITHET randomized trials.

Methods: Patients were randomized to alteplase or placebo after perfusion mismatch imaging. Reperfusion was defined as >90% reduction in Tmax>6s lesion volume at 24h. Ordinal logistic regression adjusted for baseline age and NIHSS was used to analyze functional improvement in day 90 modified Rankin scale overall, including a reperfusion*time to randomization interaction term, and in the 4.5-6h, 6-9h and wake-up time strata. Symptomatic hemorrhage was defined as large parenchymal hematoma with ≥4 point NIHSS increase (SITS).

Results: Reperfusion was assessable in 270/294 (92%) patients, 68/133 (51%) alteplase and 38/137 (28%) placebo reperfused (p<0.001). Median age 76 (IQR 66-81) in reperfused vs 74 (IQR 64.5-81) in non-reperfused, median baseline NIHSS 10 (IQR 7-15) in reperfused vs 12 (IQR 8-17.5) in non-reperfused. Overall, reperfusion was associated with common odds ratio 7.7 (95%CI 4.6-12.8, p<0.0001) in ordinal “shift” analysis. There was no heterogeneity in the beneficial effect of reperfusion effect by time to randomization (p=0.63). Reperfusion was associated with significantly improved functional outcome in each of the 4.5-6h, 6-9h and wake-up time strata (figure). Symptomatic hemorrhage, assessed in all 294 patients, occurred in 3/51 (5.9%) 4.5-6h, 2/28 (7.1%) 6-9h, 4/73 (5.5%) wake-up stroke in the alteplase-treated patients (van Elteren p=0.66).

Conclusions: Strong benefits of reperfusion in all time strata without differential risk in symptomatic hemorrhage support the durable treatment effect of alteplase in perfusion mismatch-selected patients throughout the 4.5-9h and wake-up stroke time window.

Abstract WP71: Gradient of Tissue Injury on Diffusion Tensor Imaging After Stroke: Rethinking the Infarct vs Non-infarcted Dichotomy

Objective: To evaluate the degree of variability in microstructural injury within and adjacent to regions identified as infarcted tissue using Diffusion Tensor Imaging (DTI).

Methods: Perfusion CT was performed in 18 patients within 12 hours of ischemic stroke onset followed by Fluid-attenuated Inversion recovery (FLAIR) and DTI one month after stroke. Four regions of interest (ROIs) corresponding to the severity of hypoperfusion on CT perfusion within and beyond the radiological infarct lesion defined on FLAIR were segmented. Fractional anisotropy (FA) and mean diffusivity (MD) were quantified for each ROI and compared to a mirror homologue in the contralateral hemisphere. Ipsilateral to contralateral FA and MD ratios were compared across ROIs.

Results: Lower FA and higher MD values were observed within both the infarct lesion and the peri-infarct tissue compared with their homologous contralateral brain regions (all comparisons p≤0.01). No difference was observed in FA and MD between remote non-hypoperfused tissue and its contralateral homologous region (FA p=0.42, MD p≥0.99). The magnitude of asymmetry (ipsilateral/contralateral ratios) of FA and MD was greater with increasing severity of hypoperfusion in a dose-response pattern. Asymmetry greatest in the area of infarction with severe hypoperfusion, followed by infarction with moderate hypoperfusion, the peri-infarct hypoperfused tissue and lastly the remote non-hypoperfused normal tissue (median on clustered quantile regression p≤0.01).

Conclusion: A gradient of microstructural injury corresponding to the severity of ischemic insult is present within and beyond conventionally-defined infarct boundaries. The traditional dichotomized notion of infarcted versus non-infarcted tissue widely adopted in clinical research and in practice warrants re-examination.

Abstract TMP13: Tenecteplase versus Alteplase Before Endovascular Therapy in Basilar Artery Occlusion

Background: Tenecteplase (TNK) is a genetically modified variant of alteplase with greater fibrin specificity and longer half-life than alteplase. The recent Tenecteplase versus Alteplase before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK) trial demonstrated that increased reperfusion with TNK compared to alteplase prior to endovascular thrombectomy (EVT) in large vessel occlusion ischaemic strokes. However, only 6 patients with basilar artery occlusion (BAO) were included. We aimed to investigate the efficacy of TNK versus alteplase before EVT in patients with basilar artery occlusion (BAO).

Methods: Clinical and procedural data of consecutive BAO diagnosed on CT Angiography or MR Angiography from the multisite international Basilar Artery Treatment and MANagement (BATMAN) collaboration were retrospectively analysed. The primary outcome was reperfusion of greater than 50% of the involved ischemic territory or absence of retrievable thrombus at the time of the initial angiographic assessment.

Results: We included 119 BAO patients treated with intravenous thrombolysis prior to EVT; mean age 68 (SD 14), median NIHSS 16 (IQR 7-32). Eleven patients were treated with TNK (0.25mg/kg or 0.4mg/kg) and 108 with alteplase (0.9mg/kg). Overall, 113 patients had catheter angiography or early repeat imaging after thrombolysis. Reperfusion of greater than 50% of the ischemic territory or absence of retrievable thrombus occurred in 4/11 (36%) of patients treated with TNK vs 8/102 (8%) treated with alteplase (p=0.02). Onset-to-needle time did not differ between the two groups (p=0.4). Needle-to-groin-puncture time was 61 (IQR 33-100) mins in patients reperfused with TNK vs 111 (IQR 86-198) mins in patients reperfused with alteplase (p=0.048). Overall, the rate of symptomatic haemorrhage was 3/119 (2.5%). No differences were found in the rate of symptomatic intracranial haemorrhage (p=0.3) between the two thrombolytic agents.

Conclusions: Despite shorter needle-to-groin-puncture times, tenecteplase was associated with an increased rate of reperfusion in comparison with alteplase before EVT in BAO. Randomized controlled trials to compare tenecteplase with alteplase in BAO patients before endovascular thrombectomy are warranted.

P89 Role of inflammation as a risk factor for atrial fibrillation in rheumatic mitral stenosis and its correlation with atrial late gadolinium enhancement (LGE) on cardiac MRI

Funding Acknowledgements

ICMR

Aims

Association of atrial fibrillation (AF) is a common cause of morbidity and mortality in patients with rheumatic heart disease (RHD). Association of Atrial Fibrillation with inflammation is well delineated in nonvalvular AF as compared to Rheumatic AF. This study evaluated the presence of atrial inflammation, in patients with AF and rheumatic mitral stenosis (MS), using cardiac MRI and its correlation with inflammatory markers.

Methods and Results

Twenty RHD patients with predominant mitral stenosis were recruited for the study. Ten patients had persistent AF, three had paroxysmal AF and seven were in sinus rhythm. Patients with AF had lower mitral valve areas. Cardiac MRI showed evidence of late gadolinium enhancement (LGE) in the atrial wall in 61.54% (8/13) of patients with AF as compared with only 20% (1/5; p &lt; 0.05) of patients in sinus rhythm. Mean levels of IL-6 were also significantly higher in patients with AF (10.62 ± 5.92 pg/mL versus 4.37 ± 2.68 pg/mL; P= 0.017). IL6 with a cutoff of ≥ 6.5 pg/mL was associated with a sensitivity of 76.92 % and specificity of 71.43 % for prediction of AF. There was also significant association between high IL-6 levels and LGE on MRI (13.13 ± 5.75 pg/mL vs 5.29 ± 3.23pg/mL; P &lt; 0.05)

Conclusion

Patients with MS who developed AF show evidence of atrial inflammatory sequelae in the form of fibrosis as suggested by LGE on cardiac MRI. Systemic inflammation in the form of elevated IL-6 levels correlated significantly with atrial fibrosis and AF.

Table 1: MS patients with or without AF Clinical Features Rhythm P-Value NSR (n = 7) AF (n = 13) Mean Valve Area (cm2) 1.28 ± 0.35 0.83 ± 0.26 &lt; 0.01 Mean Diastolic Gradient (mmHg) 6.29 ± 2.2 11.92 ± 5.65 &lt;0.01 Wilkin Score 7 ± 0.816 8.46 ± 1.66 0.04 LVEF % (non indexed) 59.57 ± 1.13 58.77 ± 2.89 0.49 LA Volume with MRI (ml) 127.50 ± 51.32 284.33 ± 133.12 &lt;0.01 Inflammatory Markers hs-CRP (mg/L) 5.59 ± 3.89 3.94 ± 3.47 0.34 IL6 (pg/mL) 4.37 ± 2.68 10.62 ± 5.92 0.017 sCD-40L (ng/mL) 3.72 ± 3.73 4.77 ± 2.80 0.48 Atrial LGE 0 (0%) 8 (61.5%) 0.04

Abstract P89 Figure. Image 1: Cardiac MRI showing LGE

Volatile organic compound measurements point to fog-induced biomass burning feedback to air quality in the megacity of Delhi

We report the first ambient measurements of thirteen VOCs for investigations of emissions and air quality during fog and non-fog wintertime conditions at a tower site (28.57° N, 77.11° E, 220 m amsl) in the megacity of Delhi. Measurements of acetonitrile (biomass burning (BB) tracer), isoprene (biogenic emission tracer in daytime), toluene (a traffic exhaust tracer) and benzene (emitted from BB and traffic), together with soluble and reactive oxygenated VOCs such as methanol, acetone and acetaldehyde were performed during the winters of 2015-16 and 2016-17, using proton transfer reaction mass spectrometry. Remarkably, ambient VOC composition changes during fog were not governed by solubility. Acetaldehyde, toluene, sum of C8-aromatics (e.g. xylenes), sum of C9-aromatics (e.g. trimethyl benzenes) decreased by ≥30% (>95% confidence interval), whereas acetonitrile and benzene showed significant increases by 20% (>70% confidence interval), even after accounting for boundary layer dilution. During fog, the lower temperatures appeared to induce an emissions feedback from enhanced open BB within Delhi for warming, releasing both gaseous and aerosol pollutants with consequences for fog chemistry, sustenance and intensity. The potential feedback is important to consider for improving current emission parametrizations in models used for predicting air quality and fog in such atmospheric environments.

Volumetric and Spatial Accuracy of Computed Tomography Perfusion Estimated Ischemic Core Volume in Patients With Acute Ischemic Stroke

Background and Purpose- The volume of estimated ischemic core using computed tomography perfusion (CTP) imaging can identify ischemic stroke patients who are likely to benefit from reperfusion, particularly beyond standard time windows. We assessed the accuracy of pretreatment CTP estimated ischemic core in patients with successful endovascular reperfusion. Methods- Patients from the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) and EXTEND-IA TNK (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke) databases who had pretreatment CTP, >50% angiographic reperfusion, and follow-up magnetic resonance imaging at 24 hours were included. Ischemic core volume on baseline CTP data was estimated using relative cerebral blood flow <30% (RAPID, iSchemaView). Follow-up diffusion magnetic resonance imaging was registered to CTP, and the diffusion lesion was outlined using a semiautomated algorithm. Volumetric and spatial agreement (using Dice similarity coefficient, average Hausdorff distance, and precision) was assessed, and expert visual assessment of quality was performed. Results- In 120 patients, median CTP estimated ischemic core volume was 7.8 mL (IQR, 1.8-19.9 mL), and median diffusion lesion volume at 24 hours was 30.8 mL (IQR, 14.9-67.6 mL). Median volumetric difference was 4.4 mL (IQR, 1.2-12.0 mL). Dice similarity coefficient was low (median, 0.24; IQR, 0.15-0.37). The median precision (positive predictive value) of 0.68 (IQR, 0.40-0.88) and average Hausdorff distance (median, 3.1; IQR, 1.8-5.7 mm) indicated reasonable spatial agreement for regions estimated as ischemic core at baseline. Overestimation of total ischemic core volume by CTP was uncommon. Expert visual review revealed overestimation predominantly in white matter regions. Conclusions- CTP estimated ischemic core volumes were substantially smaller than follow-up diffusion-weighted imaging lesions at 24 hours despite endovascular reperfusion within 2 hours of imaging. This may be partly because of infarct growth. Volumetric CTP core overestimation was uncommon and not related to imaging-to-reperfusion time. Core overestimation in white matter should be a focus of future efforts to improve CTP accuracy.

Ecological footprint, urbanization, and energy consumption in South Africa: including the excluded

The study explores the relationship between ecological footprint, urbanization, and energy consumption by applying the ARDL estimation technique on data spanning 1965-2014 for South Africa. After applying the unit root test that accounts for a break in the data, the Bayer and Hanck (J Time Ser Anal 34:83-95, 2013) combined cointegration test affirms cointegrating relationship among the variables. Findings further reveal that economic growth and financial development exact a deteriorating impact on the environment in the short run. However, the same was not true for both energy use and urbanization. While urbanization and energy use promote environmental quality in the long run, financial development and economic growth degrade it further. The long-run findings of our study are confirmed to be robust as reported by the fully modified OLS (FMOLS), dynamic OLS (DOLS), and the canonical cointegrating regression (CCR) estimates. The direction of causality supports the energy-led growth hypothesis for South Africa. Policy outcomes and directions, and the possibility of promoting sustainable growth without degrading the environment are discussed.