Tranexamic acid versus placebo in individuals with intracerebral haemorrhage treated within 2 h of symptom onset (STOP-MSU): an international, double-blind, randomised, phase 2 trial

BACKGROUND

Tranexamic acid, an antifibrinolytic agent, might attenuate haematoma growth after an intracerebral haemorrhage. We aimed to determine whether treatment with intravenous tranexamic acid within 2 h of an intracerebral haemorrhage would reduce haematoma growth compared with placebo.

METHODS

STOP-MSU was an investigator-led, double-blind, randomised, phase 2 trial conducted at 24 hospitals and one mobile stroke unit in Australia, Finland, New Zealand, Taiwan, and Viet Nam. Eligible participants had acute spontaneous intracerebral haemorrhage confirmed on non-contrast CT, were aged 18 years or older, and could be treated with the investigational product within 2 h of stroke onset. Using randomly permuted blocks (block size of 4) and a concealed pre-randomised assignment procedure, participants were randomly assigned (1:1) to receive intravenous tranexamic acid (1 g over 10 min followed by 1 g over 8 h) or placebo (saline; matched dosing regimen) commencing within 2 h of symptom onset. Participants, investigators, and treating teams were masked to group assignment. The primary outcome was haematoma growth, defined as either at least 33% relative growth or at least 6 mL absolute growth on CT at 24 h (target range 18-30 h) from the baseline CT. The analysis was conducted within the estimand framework with primary analyses adhering to the intention-to-treat principle. The primary endpoint and secondary safety endpoints (mortality at days 7 and 90 and major thromboembolic events at day 90) were assessed in all participants randomly assigned to treatment groups who did not withdraw consent to use any data. This study was registered with ClinicalTrials.gov, NCT03385928, and the trial is now complete.

FINDINGS

Between March 19, 2018, and Feb 27, 2023, 202 participants were recruited, of whom one withdrew consent for any data use. The remaining 201 participants were randomly assigned to either placebo (n=98) or tranexamic acid (n=103; intention-to-treat population). Median age was 66 years (IQR 55-77), and 82 (41%) were female and 119 (59%) were male; no data on race or ethnicity were collected. CT scans at baseline or follow-up were missing or of inadequate quality in three participants (one in the placebo group and two in the tranexamic acid group), and were considered missing at random. Haematoma growth occurred in 37 (38%) of 97 assessable participants in the placebo group and 43 (43%) of 101 assessable participants in the tranexamic acid group (adjusted odds ratio [aOR] 1·31 [95% CI 0·72 to 2·40], p=0·37). Major thromboembolic events occurred in one (1%) of 98 participants in the placebo group and three (3%) of 103 in the tranexamic acid group (risk difference 0·02 [95% CI -0·02 to 0·06]). By 7 days, eight (8%) participants in the placebo group and eight (8%) in the tranexamic acid group had died (aOR 1·08 [95% CI 0·35 to 3·35]) and by 90 days, 15 (15%) participants in the placebo group and 19 (18%) in the tranexamic acid group had died (aOR 1·61 [95% CI 0·65 to 3·98]).

INTERPRETATION

Intravenous tranexamic acid did not reduce haematoma growth when administered within 2 h of intracerebral haemorrhage symptom onset. There were no observed effects on other imaging endpoints, functional outcome, or safety. Based on our results, tranexamic acid should not be used routinely in primary intracerebral haemorrhage, although results of ongoing phase 3 trials will add further context to these findings.

FUNDING

Australian Government Medical Research Future Fund.

Baseline perihematomal edema, C-reactive protein, and 30-day mortality are not associated in intracerebral hemorrhage

Background

The relationship between baseline perihematomal edema (PHE) and inflammation, and their impact on survival after intracerebral hemorrhage (ICH) are not well understood.

Objective

Assess the association between baseline PHE, baseline C-reactive protein (CRP), and early death after ICH.

Methods

Analysis of pooled data from multicenter ICH registries. We included patients presenting within 24 h of symptom onset, using multifactorial linear regression model to assess the association between CRP and edema extension distance (EED), and a multifactorial Cox regression model to assess the association between CRP, PHE volume and 30-day mortality.

Results

We included 1,034 patients. Median age was 69 (interquartile range [IQR] 59-79), median baseline ICH volume 11.5 (IQR 4.3-28.9) mL, and median baseline CRP 2.5 (IQR 1.5-7.0) mg/L. In the multifactorial analysis [adjusting for cohort, age, sex, log-ICH volume, ICH location, intraventricular hemorrhage (IVH), statin use, glucose, and systolic blood pressure], baseline log-CRP was not associated with baseline EED: for a 50% increase in CRP the difference in expected mean EED was 0.004 cm (95%CI 0.000-0.008, p = 0.055). In a further multifactorial analysis, after adjusting for key predictors of mortality, neither a 50% increase in PHE volume nor CRP were associated with higher 30-day mortality (HR 0.97; 95%CI 0.90-1.05, p = 0.51 and HR 0.98; 95%CI 0.93-1.03, p = 0.41, respectively).

Conclusion

Higher baseline CRP is not associated with higher baseline edema, which is also not associated with mortality. Edema at baseline might be driven by different pathophysiological processes with different effects on outcome.

Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles

Importance

Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain.

Objective

To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect.

Design, Setting, and Participants

An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022.

Intervention

EVT vs MM.

Main Outcomes and Measures

Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI.

Results

Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled.

Conclusion and Relevance

In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

A prospective case-control study on the evaluation of oxidative stress in renal stone formers

Association of increased oxidative stress (OS) with the pathophysiology of renal stone formation has not been explored greatly in the field of urolithiasis. In this prospective case-control study, we measured 24-h urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in patients with urolithiasis and compared them with matched healthy controls. We also measured 24-h urinary uric acid, calcium, oxalate, and citrate levels in patients with renal stone disease and studied their relation with urinary 8-OHdG levels. Seventy-five cases of renal stone disease and 75 well-matched controls were included. Median 24-h urinary 8-OHdG levels were significantly higher in cases compared to controls (7.6 vs. 3.7 µg/g of creatinine; p < 0.000). Receiver-operating curve (ROC) analysis for 8-OHdG between cases and controls revealed an area under the curve of 0.90. At 8-OHdG (µg/g of creatinine) value of 5 or more, a sensitivity and a specificity of 84% each were obtained. A positive correlation between 8-OHdG (µg/g of creatinine) and 24-h urinary oxalate level was noted (r = 0.461, p = 0.000). No correlation between 8-OHdG (µg/g of creatinine) and other variables was noted. On multivariate linear regression analysis, we noted 24-h urinary oxalate levels to be an independent predictor of urinary 8-OHdG levels. OS is significantly higher in patients with renal stone diseases compared to healthy controls. Urinary oxalate levels were significantly correlated with urinary 8-OHdG levels.

Disease-specific wearable sensor algorithms for profiling activity, gait, and balance in individuals with Charcot-Marie-Tooth disease type 1A

BACKGROUND/AIMS

Charcot-Marie-Tooth Disease type 1A (CMT1A), the most common inherited peripheral neuropathy, is characterized by progressive sensory loss and weakness, which results in impaired mobility. Increased understanding of the genetics and pathophysiology of CMT1A has led to development of potential therapeutic agents, necessitating clinical trial readiness. Wearable sensors may provide useful outcome measures for future trials.

METHODS

Individuals with CMT1A and unaffected controls were recruited for this 12-month study. Participants wore sensors for in-clinic assessments and at-home, from which activity, gait, and balance metrics were derived. Mann-Whitney U tests were used to analyze group differences for activity, gait, and balance parameters. Test-retest reliability of gait and balance parameters and correlations of these parameters with clinical outcome assessments (COAs) were examined.

RESULTS

Thirty individuals, 15 CMT1A, and 15 controls, participated. Gait and balance metrics demonstrated moderate to excellent reliability. CMT1A participants had longer step durations (p < .001), shorter step lengths (p = .03), slower gait speeds (p < .001), and greater postural sway (p < .001) than healthy controls. Moderate correlations were found between CMT-Functional Outcome Measure and step length (r = -0.59; p = .02), and gait speed (r = 0.64; p = .01); 11 out of 15 CMT1A participants demonstrated significant increases in stride duration between the first and last quarter of the 6-min walk test, suggesting fatigue.

INTERPRETATION

In this initial study, gait and balance metrics derived from wearable sensors were reliable and associated with COAs in individuals with CMT1A. Larger longitudinal studies are needed to confirm our findings and evaluate sensitivity and utility of these disease-specific algorithms for clinical trial use.

Safety and Efficacy of Tenecteplase and Alteplase in Patients With Tandem Lesion Stroke: A Post Hoc Analysis of the EXTEND-IA TNK Trials

BACKGROUND AND OBJECTIVES

The safety and efficacy of tenecteplase (TNK) in patients with tandem lesion (TL) stroke is unknown. We performed a comparative analysis of TNK and alteplase in patients with TLs.

METHODS

We first compared the treatment effect of TNK and alteplase in patients with TLs using individual patient data from the EXTEND-IA TNK trials. We evaluated intracranial reperfusion at initial angiographic assessment and 90-day modified Rankin scale (mRS) with ordinal logistic and Firth regression models. Because 2 key outcomes, mortality and symptomatic intracranial hemorrhage (sICH), were few in number among those who received alteplase in the EXTEND-IA TNK trials, we generated pooled estimates for these outcomes by supplementing trial data with estimates of incidence obtained through a meta-analysis of studies identified in a systematic review. We then calculated unadjusted risk differences to compare the pooled estimates for those receiving alteplase with the incidence observed in the trial among those receiving TNK.

RESULTS

Seventy-one of 483 patients (15%) in the EXTEND-IA TNK trials possessed a TL. In patients with TLs, intracranial reperfusion was observed in 11/56 (20%) of TNK-treated patients vs 1/15 (7%) alteplase-treated patients (adjusted odds ratio 2.19; 95% CI 0.28-17.29). No significant difference in 90-day mRS was observed (adjusted common odds ratio 1.48; 95% CI 0.44-5.00). A pooled study-level proportion of alteplase-associated mortality and sICH was 0.14 (95% CI 0.08-0.21) and 0.09 (95% CI 0.04-0.16), respectively. Compared with a mortality rate of 0.09 (95% CI 0.03-0.20) and an sICH rate of 0.07 (95% CI 0.02-0.17) in TNK-treated patients, no significant difference was observed.

DISCUSSION

Functional outcomes, mortality, and sICH did not significantly differ between patients with TLs treated with TNK and those treated with alteplase.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that TNK is associated with similar rates of intracranial reperfusion, functional outcome, mortality, and sICH compared with alteplase in patients with acute stroke due to TLs. However, the CIs do not rule out clinically important differences. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov/ct2/show/NCT02388061; clinicaltrials.gov/ct2/show/NCT03340493.

Trial of Endovascular Thrombectomy for Large Ischemic Strokes

BACKGROUND

Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations.

METHODS

We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome.

RESULTS

The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group.

CONCLUSIONS

Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Tenecteplase Treatment and Thrombus Characteristics Associated With Early Reperfusion: An EXTEND-IA TNK Trials Analysis

BACKGROUND

Intracranial occlusion site, contrast permeability, and clot burden are thrombus characteristics that influence alteplase-associated reperfusion. In this study, we assessed the reperfusion efficacy of tenecteplase and alteplase in subgroups based on these characteristics in a pooled analysis of the EXTEND-IA TNK trial (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke).

METHODS

Patients with large vessel occlusion were randomized to treatment with tenecteplase (0.25 or 0.4 mg/kg) or alteplase before thrombectomy in hospitals across Australia and New Zealand (2015-2019). The primary outcome, early reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion on first-pass angiogram. We compared the effect of tenecteplase versus alteplase overall, and in subgroups, based on the following measured with computed tomography angiography: intracranial occlusion site, contrast permeability (measured via residual flow grades), and clot burden (measured via clot burden scores). We adjusted for covariates using mixed effects logistic regression models.

RESULTS

Tenecteplase was associated with higher odds of early reperfusion (75/369 [20%] versus alteplase: 9/96 [9%], adjusted odds ratio [aOR], 2.18 [95% CI, 1.03-4.63]). The difference between thrombolytics was notable in occlusions with low clot burden (tenecteplase: 66/261 [25%] versus alteplase: 5/67 [7%], aOR, 3.93 [95% CI, 1.50-10.33]) when compared to high clot burden lesions (tenecteplase: 9/108 [8%] versus alteplase: 4/29 [14%], aOR, 0.58 [95% CI, 0.16-2.06]; P_interaction=0.01). We did not observe an association between contrast permeability and tenecteplase treatment effect (permeability present: aOR, 2.83 [95% CI, 1.00-8.05] versus absent: aOR, 1.98 [95% CI, 0.65-6.03]; P_interaction=0.62). Tenecteplase treatment effect was superior with distal M1 or M2 occlusions (53/176 [30%] versus alteplase: 4/42 [10%], aOR, 3.73 [95% CI, 1.25-11.11]), but both thrombolytics had limited efficacy with internal carotid artery occlusions (tenecteplase 1/73 [1%] versus alteplase 1/19 [5%], aOR, 0.22 [95% CI, 0.01-3.83]; P_interaction=0.16).

CONCLUSIONS

Tenecteplase demonstrates superior early reperfusion versus alteplase in lesions with low clot burden. Reperfusion efficacy remains limited in internal carotid artery occlusions and lesions with high clot burden. Further innovation in thrombolytic therapies are required.

Tenecteplase Improves Reperfusion across Time in Large Vessel Stroke

OBJECTIVE

Tenecteplase improves reperfusion compared to alteplase in patients with large vessel occlusions. To determine whether this improvement varies across the spectrum of thrombolytic agent to reperfusion assessment times, we performed a comparative analysis of tenecteplase and alteplase reperfusion rates.

METHODS

Patients with large vessel occlusion and treatment with thrombolysis were pooled from the Melbourne Stroke Registry, and the EXTEND-IA and EXTEND-IA TNK trials. The primary outcome, thrombolytic-induced reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion at imaging reassessment. We compared the treatment effect of tenecteplase and alteplase, accounting for thrombolytic to assessment exposure times, via Poisson modeling. We compared 90-day outcomes of patients who achieved reperfusion with a thrombolytic to patients who achieved reperfusion via endovascular therapy using ordinal logistic regression.

RESULTS

Among 893 patients included in the primary analysis, thrombolytic-induced reperfusion was observed in 184 (21%) patients. Tenecteplase was associated with higher rates of reperfusion (adjusted incidence rate ratio [aIRR] = 1.50, 95% confidence interval [CI] = 1.09-2.07, p = 0.01). Findings were consistent in patient subgroups with first segment (aIRR = 1.41, 95% CI = 0.93-2.14) and second segment (aIRR = 2.07, 95% CI = 0.98-4.37) middle cerebral artery occlusions. Increased thrombolytic to reperfusion assessment times were associated with reperfusion (tenecteplase: adjusted risk ratio [aRR] = 1.08 per 15 minutes, 95% CI = 1.04-1.13 vs alteplase: aRR = 1.06 per 15 minutes, 95% CI = 1.00-1.13). No significant treatment-by-time interaction was observed (p = 0.87). Reperfusion via thrombolysis was associated with improved 90-day modified Rankin Scale scores (adjusted common odds ratio = 2.15, 95% CI = 1.54-3.01) compared to patients who achieved reperfusion following endovascular therapy.

INTERPRETATION

Tenecteplase, compared to alteplase, increases prethrombectomy reperfusion, regardless of the time from administration to reperfusion assessment. Prethrombectomy reperfusion is associated with better clinical outcomes. ANN NEUROL 2023;93:489-499.

Is tranexamic acid associated with decreased need for blood transfusion in percutaneous nephrolithotomy: a systematic review and meta-analysis

INTRODUCTION

Bleeding is a common complication after percutaneous nephrolithotomy (PNL) for renal stone disease. Tranexamic acid (TXA) has been found to reduce mortality and blood transfusion in surgical and trauma patients. This review aimed to assess the safety and efficacy of TXA in patients undergoing PNL.

METHODS

A systematic literature review was performed to recognise all randomised controlled trials (RCTs) comparing the use of TXA in PNL. The primary outcome of the study was to compare the need for blood transfusion with and without TXA.

FINDINGS

Six RCTs with 1,323 patients were included in this review. Haemoglobin fall was lower in the TXA group compared with the control group, and the need for blood transfusion was reduced by 67% (odds ratio (OR) 0.33, confidence interval (CI) (0.21, 0.52), p<0.00001). However, blood loss was comparable for the two groups (mean difference -116.9, CI (-244.5,10.7) p=0.07). Length of stay and duration of surgery was significantly shorter with TXA. Furthermore, both minor and major complications were lower in the TXA group. Stone-free rate was higher with the TXA group. No thromboembolic complications were noted in the TXA group.

CONCLUSIONS

TXA is safe and efficacious for PNL with a reduction in need for blood transfusion and without an attending increase in complication rates.

[Pharmacological importance of novel spiro derivatives against human pathogenic fungi]

Human mycoses have become a threat to health world-wide. Unfortunately there are only a limited number of antimycotic drugs in use. In the present study, antifungal activity of earlier synthesized spiro-1,4-dihydropyridines (1,4-DHPs) was investigated. The antifungal activity of spiro-1,4-DHPs compounds were screened against Aspergillus flavus, A. fumigatus, and Candida albicans by using Disc Diffusion and Modified Microdilution method. Among six spiro-1,4-DHPs compounds tested all of them showed stronger antifungal activity possibly through inhibiting the synthesis of chitin in cell wall against A. flavus, A. fumigatus, and C. albicans as compared to fluconazole, a standard antifungal drug. The combination of compounds showed that the synthesized compounds had synergistic, additive effects as compared to currently used drugs as an antifungal agent. These results indicated that these designed compounds were potential chitin synthase inhibitors and had excellent antimycotic activity for the treatment of fungal infections.

Abstract 92: Tenecteplase Treatment And Thrombus Characteristics Associated With Early Reperfusion - An EXTEND-IA TNK Trials Analysis

Background: Intracranial occlusion site, contrast permeability, and clot burden are thrombus characteristics that influence alteplase-associated reperfusion. In this study, we assessed the reperfusion efficacy of tenecteplase and alteplase in subgroups based on these characteristics in a pooled analysis of the EXTEND-IA TNK trials.

Methods: Patients with large vessel occlusion (LVO) were randomized to treatment with tenecteplase (0.25mg/kg or 0.4mg/kg) or alteplase (0.9mg/kg) prior to thrombectomy. The primary outcome, early reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion on initial angiographic assessment. We compared the treatment effect of tenecteplase versus alteplase overall, and in subgroups based on intracranial occlusion site, the presence of contrast permeability (measured via residual flow grades), and clot burden (measured via clot burden scores), whilst adjusting for relevant covariates using mixed effects logistic regression models.

Results: Among the 465 patients in the primary analysis, early reperfusion occurred in 18% (84/465). Tenecteplase was associated with a higher odds of early reperfusion (tenecteplase: 75/369 [20%] vs. alteplase: 9/96 [9%], aOR: 2.18 [95%CI: 1.03-4.63]). The difference between thrombolytics was most notable in distal M1 or M2 occlusions (tenecteplase: 53/176 [30%] vs. alteplase: 4/42 [10%], aOR: 3.73 [95%CI: 1.25-11.11]), thrombi with contrast permeability (tenecteplase: 38/160 [24%] vs. alteplase: 5/48 [10%], aOR: 2.83 [95%CI: 1.00-8.05]), and in low clot burden occlusions (tenecteplase: 66/261 [25%] vs. alteplase: 5/67 [7%], aOR: 3.93 [95%CI: 1.50-10.33]). Both thrombolytics had limited early reperfusion efficacy in proximal occlusions (ICA: tenecteplase 1/73 [1%] vs. alteplase 1/19 [5%]) and in high clot burden occlusions (tenecteplase: 9/108 [8%] vs. alteplase: 4/29 [14%], aOR: 0.58 [95%CI: 0.16-2.06]).

Conclusions: Tenecteplase demonstrates superior early reperfusion versus alteplase in distal LVO, in contrast-permeable thrombi, and in lesions with low clot burden. Reperfusion efficacy remains limited in ICA occlusions and lesions with high clot burden. Further improvements in intravenous thrombolytics are required.

Thrombectomy Outcomes With General vs Nongeneral Anesthesia: A Pooled Patient-Level Analysis From the EXTEND-IA Trials and SELECT Study

BACKGROUND AND OBJECTIVES

The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice.

METHODS

In a pooled patient-level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II, and SELECT, EVT functional outcomes (modified Rankin Scale score distribution) were compared between general anesthesia (GA) vs non-GA in a propensity-matched sample. Furthermore, we evaluated the association of collateral flow on perfusion imaging, assessed by hypoperfusion intensity ratio (HIR) - Tmax > 10 seconds/Tmax > 6 seconds (good collaterals - HIR < 0.4, poor collaterals - HIR ≥ 0.4) on the association between anesthesia type and EVT outcomes.

RESULTS

Of 725 treated with EVT, 299 (41%) received GA and 426 (59%) non-GA. The baseline characteristics differed in presentation National Institutes of Health Stroke Scale score (median [interquartile range] GA: 18 [13-22], non-GA: 16 [11-20], p < 0.001) and ischemic core volume (GA: 15.0 mL [3.2-38.0] vs non-GA: 9.0 mL [0.0-31.0], p < 0.001). In addition, GA was associated with longer last known well to arterial access (203 minutes [157-267] vs 186 minutes [138-252], p = 0.002), but similar procedural time (35.5 minutes [23-59] vs 34 minutes [22-54], p = 0.51). Of 182 matched pairs using propensity scores, baseline characteristics were similar. In the propensity score-matched pairs, GA was independently associated with worse functional outcomes (adjusted common odds ratio [adj. cOR]: 0.64, 95% CI: 0.44-0.93, p = 0.021) and higher neurologic worsening (GA: 14.9% vs non-GA: 8.9%, aOR: 2.10, 95% CI: 1.02-4.33, p = 0.045). Patients with poor collaterals had worse functional outcomes with GA (adj. cOR: 0.47, 95% CI: 0.29-0.76, p = 0.002), whereas no difference was observed in those with good collaterals (adj. cOR: 0.93, 95% CI: 0.50-1.74, p = 0.82), p interaction: 0.07. No difference was observed in infarct growth overall and in patients with good collaterals, whereas patients with poor collaterals demonstrated larger infarct growth with GA with a significant interaction between collaterals and anesthesia type on infarct growth rate (p interaction: 0.020).

DISCUSSION

GA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals in a propensity score-matched analysis from a pooled patient-level cohort from 3 randomized trials and 1 prospective cohort study. The confounding by indication may persist despite the doubly robust nature of the analysis. These findings have implications for randomized trials of GA vs non-GA and may be of utility for clinicians when making anesthesia type choice.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that use of GA is associated with worse functional outcome in patients undergoing EVT.

TRIAL REGISTRATION INFORMATION

EXTEND-IA: ClinicalTrials.gov (NCT01492725); EXTEND-IA TNK: ClinicalTrials.gov (NCT02388061); EXTEND-IA TNK part II: ClinicalTrials.gov (NCT03340493); and SELECT: ClinicalTrials.gov (NCT02446587).

Mediation of Successful Reperfusion Effect through Infarct Growth and Cerebral Edema: A Pooled, Patient-Level Analysis of EXTEND-IA Trials and SELECT Prospective Cohort

OBJECTIVE

Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship.

METHODS

In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift.

RESULTS

A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (β = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results.

INTERPRETATION

In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023.

Patterns and outcomes of cardiovascular emergency department encounters for men and women in the USA

Aims

We described sex-differential disease patterns and outcomes of over 20.6 million cardiovascular emergency department (ED) encounters in the USA.

Methods and results

We analysed primary cardiovascular encounters from the Nationwide Emergency Department Sample (between 2016–2018). We grouped the documented cardiovascular diagnoses into 15 disease categories. The sample included 48.7% women; average age was 67 [54,78] years. Men had greater overall baseline co-morbidity burden; however, women had higher rates of obesity, hypertension, and cerebrovascular disease. For women, the most common ED encounters were essential hypertension (16.0%), hypertensive heart or kidney disease (14.1%), and atrial fibrillation (AF)/flutter (10.2%). For men, the most common encounters were hypertensive heart or kidney disease (14.7%), essential hypertension (10.8%), and acute myocardial infarction (AMI, 10.7%). Women were more likely to present with essential hypertension, hypertensive crisis, AF/flutter, supraventricular tachycardia, pulmonary embolism, or ischaemic stroke. Men were more likely to present with AMI or cardiac arrest. In logistic regression models adjusted for baseline covariates, women with intracranial haemorrhage had higher risk of hospitalisation and death. Women with ischaemic stroke had higher risk of hospitalisation and death in ED. Women presenting with pulmonary embolism were less likely to be hospitalised but were more likely to die. Women with aortic aneurysm/dissection had higher risk of hospitalisation and death. Men were more likely to die following presentations with hypertensive heart or kidney disease, AF/flutter, AMI, or cardiac arrest.

Conclusion

In this large nationally representative sample of cardiovascular ED presentations, we demonstrate significant sex differences in disease distribution, hospitalisation, and death.

Funding Acknowledgement

Type of funding sources: None.

Effects of high glutamate concentrations on mitochondria of human neuroblastoma SH-SY5Y cells

BACKGROUND

The excess amount of glutamate in neurons is associated with the excitotoxicity and neurodegenerative diseases. Glutamate induces neurotoxicity primarily by immense influx of Ca²⁺ arising from overstimulation of the NMDA subtype of glutamate receptors. The neuronal death induced by the overstimulation of glutamate receptors depends critically on a sustained increase in mitochondrial Ca²⁺ influx and impairment in mitochondrial functions. The mitochondrial impairment is an important contributor to the glutamate-induced neuronal toxicity and thus provides an important target for the intervention. The present study investigates the effects of high glutamate concentrations on mitochondrial functions.

RESULTS

Here, we have shown that the higher concentration of glutamate treatment caused a significant elevation in the N-methyl-D-aspartate (NMDA) receptors expression and elevated the intra-mitochondrial calcium accumulation in SHSY5Y neuronal cells. As a result of an accumulation of intra-mitochondrial calcium, there is a concentration-dependent elevation in ROS in the mitochondria. Tyrosine nitration of several mitochondrial proteins was increased while the mitochondrial membrane potential was dissipated. Furthermore, glutamate treatments also resulted in mitochondrial membrane permeability transition.

CONCLUSIONS

These findings suggest that treatment of high glutamate concentration causes impairment of mitochondrial functions by an increase in intra-mitochondrial calcium, ROS production, dissipation of mitochondrial membrane potential and mitochondrial permeability transition pore opening in human neuroblastoma SHSY5Y cells.

Comparison of Computed Tomography Perfusion and Multiphase Computed Tomography Angiogram in Predicting Clinical Outcomes in Endovascular Thrombectomy

BACKGROUND

In patients with acute stroke who undergo endovascular thrombectomy, the relative prognostic power of computed tomography perfusion (CTP) parameters compared with multiphase CT angiogram (mCTA) is unknown. We aimed to compare the predictive accuracy of mCTA and CTP parameters on clinical outcomes.

METHODS

We included patients with acute ischemic stroke who had anterior circulation large vessel occlusion within 24 hours of onset in Melbourne Brain Centre at the Royal Melbourne Hospital. All patients underwent CTP for endovascular thrombectomy, and the mCTA collateral score was determined using CTP-reconstructed mCTA images. The primary outcome was 90-day functional outcomes defined by modified Rankin Scale. Multivariable logistic regression models analyzed associations between mCTA and CTP parameters and 90-day functional outcomes. The ability to discriminate 90 days-functional outcomes was compared between mCTA collateral score and CTP parameters using receiver operating curve analysis and C statistics.

RESULTS

One hundred and twenty patients were included. The median age was 69 years (interquartile range, 60-79), the median baseline National Institutes of Health Stroke Scale score was 14 (interquartile range, 9-19). The baseline ischemic core volume, defined by CTP-based relative cerebral blood flow <30%, was associated with excellent functional outcome (modified Rankin Scale score 0-1; odds ratio, 0.942 [-0.897 to -0.989]; P=0.015) and poor functional outcome (modified Rankin Scale score 5-6; odds ratio, 1.032 [1.007-1.056]; P=0.010) at 90 days in the analysis of multivariable regression. There was no significant association between the mCTA score and excellent functional outcome (P=0.58) or poor functional outcome (P=0.155). The relative cerebral blood flow <30%-based regression model best fit the data for the 90-day poor functional outcome (C statistic, 0.834).

CONCLUSIONS

The CTP-based ischemic core volume may provide better discrimination for 90-day functional outcomes for patients with acute stroke undergoing endovascular thrombectomy than the mCTA collateral score.

Accuracy of CT Perfusion-Based Core Estimation of Follow-up Infarction: Effects of Time Since Last Known Well

BACKGROUND AND OBJECTIVES

To assess the accuracy of baseline CT perfusion (CTP) ischemic core estimates.

METHODS

From SELECT (Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke), a prospective multicenter cohort study of imaging selection, patients undergoing endovascular thrombectomy who achieved complete reperfusion (modified Thrombolysis In Cerebral Ischemia score 3) and had follow-up diffusion-weighted imaging (DWI) available were evaluated. Follow-up DWI lesions were coregistered to baseline CTP. The difference between baseline CTP core (relative cerebral blood flow [rCBF] <30%) volume and follow-up infarct volume was classified as overestimation (core ≥10 mL larger than infarct), adequate, or underestimation (core ≥25 mL smaller than infarct) and spatial overlap was evaluated.

RESULTS

Of 101 included patients, median time from last known well (LKW) to imaging acquisition was 138 (82-244) minutes. The median baseline ischemic core estimate was 9 (0-31.9) mL and median follow-up infarct volume was 18.4 (5.3-68.7) mL. All 6/101 (6%) patients with overestimation of the subsequent infarct volume were imaged within 90 minutes of LKW and achieved rapid reperfusion (within 120 minutes of CTP). Using rCBF <20% threshold to estimate ischemic core in patients presenting within 90 minutes eliminated overestimation. Volumetric correlation between the ischemic core estimate and follow-up imaging improved as LKW time to imaging acquisition increased: Spearman ρ <90 minutes 0.33 (p = 0.049), 90-270 minutes 0.63 (p < 0.0001), >270 minutes 0.86 (p < 0.0001). Assessment of the spatial overlap between baseline CTP ischemic core lesion and follow-up infarct demonstrated that a median of 3.2 (0.0-9.0) mL of estimated core fell outside the subsequent infarct. These regions were predominantly in white matter.

DISCUSSION

Significant overestimation of irreversibly injured ischemic core volume was rare, was only observed in patients who presented within 90 minutes of LKW and achieved reperfusion within 120 minutes of CTP acquisition, and occurred primarily in white matter. Use of a more conservative (rCBF <20%) threshold for estimating ischemic core in patients presenting within 90 minutes eliminated all significant overestimation cases.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov: NCT03876457.

Residual ctDNA after treatment predicts early relapse in patients with early-stage non-small cell lung cancer

BACKGROUND

Identification of residual disease in patients with localized non-small cell lung cancer (NSCLC) following treatment with curative intent holds promise to identify patients at risk of relapse. New methods can detect circulating tumour DNA (ctDNA) in plasma to fractional concentrations as low as a few parts per million, and clinical evidence is required to inform their use.

PATIENTS AND METHODS

We analyzed 363 serial plasma samples from 88 patients with early-stage NSCLC (48.9%/28.4%/22.7% at stage I/II/III), predominantly adenocarcinomas (62.5%), treated with curative intent by surgery (n = 61), surgery and adjuvant chemotherapy/radiotherapy (n = 8), or chemoradiotherapy (n = 19). Tumour exome sequencing identified somatic mutations and plasma was analyzed using patient-specific RaDaR™ assays with up to 48 amplicons targeting tumour-specific variants unique to each patient.

RESULTS

ctDNA was detected before treatment in 24%, 77% and 87% of patients with stage I, II and III disease, respectively, and in 26% of all longitudinal samples. The median tumour fraction detected was 0.042%, with 63% of samples <0.1% and 36% of samples <0.01%. ctDNA detection had clinical specificity >98.5% and preceded clinical detection of recurrence of the primary tumour by a median of 212.5 days. ctDNA was detected after treatment in 18/28 (64.3%) of patients who had clinical recurrence of their primary tumour. Detection within the landmark timepoint 2 weeks to 4 months after treatment end occurred in 17% of patients, and was associated with shorter recurrence-free survival [hazard ratio (HR): 14.8, P <0.00001] and overall survival (HR: 5.48, P <0.0003). ctDNA was detected 1-3 days after surgery in 25% of patients yet was not associated with disease recurrence. Detection before treatment was associated with shorter overall survival and recurrence-free survival (HR: 2.97 and 3.14, P values 0.01 and 0.003, respectively).

CONCLUSIONS

ctDNA detection after initial treatment of patients with early-stage NSCLC using sensitive patient-specific assays has potential to identify patients who may benefit from further therapeutic intervention.

Correlation Between Computed Tomography-Based Tissue Net Water Uptake and Volumetric Measures of Cerebral Edema After Reperfusion Therapy

BACKGROUND

Cerebral edema after large hemispheric infarction is associated with poor functional outcome and mortality. Net water uptake (NWU) quantifies the degree of hypoattenuation on unenhanced-computed tomography (CT) and is increasingly used to measure cerebral edema in stroke research. Hemorrhagic transformation and parenchymal contrast staining after thrombectomy may confound NWU measurements. We investigated the correlation of NWU measured postthrombectomy with volumetric markers of cerebral edema and association with functional outcomes.

METHODS

In a pooled individual patient level analysis of patients presenting with anterior circulation large hemispheric infarction (core 80-300 mL or Alberta Stroke Program Early CT Score ≤5) in the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke trials) data set, cerebral edema was defined as the volumetric expansion of the ischemic hemisphere expressed as a ratio to the contralateral hemisphere(rHV). NWU and midline-shift were compared with rHV as the reference standard on 24-hour follow-up CT, adjusted for hemorrhagic transformation and the use of thrombectomy. Association between edema markers and day 90 functional outcomes (modified Rankin Scale) was assessed using ordinal logistic regression.

RESULTS

Overall (n=144), there was no correlation between NWU and rHV (r_s=0.055, P=0.51). In sub-group analyses, a weak correlation between NWU with rHV was observed after excluding patients with any degree of hemorrhagic transformation (r_s=0.211, P=0.015), which further improved after excluding thrombectomy patients (r_s=0.453, P=0.001). Midline-shift correlated strongly with rHV in all sub-group analyses (r_s>0.753, P=0.001). Functional outcome at 90 days was negatively associated with rHV (adjusted common odds ratio, 0.46 [95% CI, 0.32-0.65]; P<0.001) and midline-shift (adjusted common odds ratio, 0.85 [95% CI, 0.78-0.92]; P<0.001) but not NWU (adjusted common odds ratio, 1.00 [95% CI, 0.97-1.03]; P=0.84), adjusted for age, baseline National Institutes of Health Stroke Scale, and thrombectomy. Prognostic performance of NWU improved after excluding patients with hemorrhagic transformation and thrombectomy (adjusted odds ratio, 0.90 [95% CI, 0.80-1.02]; P=0.10).

CONCLUSIONS

NWU correlated poorly with conventional markers of cerebral edema and was not associated with clinical outcome in the presence of hemorrhagic transformation and thrombectomy. Measuring NWU postthrombectomy requires validation before implementation into clinical research. At present, the use of NWU should be limited to baseline CT, or follow-up CT only in patients without hemorrhagic transformation or treatment with thrombectomy.

Prevalence and Significance of Impaired Microvascular Tissue Reperfusion Despite Macrovascular Angiographic Reperfusion (No-Reflow)

BACKGROUND AND OBJECTIVES

The relevance of impaired microvascular tissue-level reperfusion despite complete upstream macrovascular angiographic reperfusion (no-reflow) in human stroke remains controversial. We investigated the prevalence and clinical-radiologic features of this phenomenon and its associations with outcomes in 3 international randomized controlled thrombectomy trials with prespecified follow-up perfusion imaging.

METHODS

In a pooled analysis of the Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial (EXTEND-IA; ClinicalTrials.gov NCT01492725), Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK; NCT02388061), and Determining the Optimal Dose of Tenecteplase Before Endovascular Therapy for Ischaemic Stroke (EXTEND-IA TNK Part 2; NCT03340493) trials, patients undergoing thrombectomy with final angiographic expanded Treatment in Cerebral Infarction score of 2c to 3 score for anterior circulation large vessel occlusion and 24-hour follow-up CT or MRI perfusion imaging were included. No-reflow was defined as regions of visually demonstrable persistent hypoperfusion on relative cerebral blood volume or flow maps within the infarct and verified quantitatively by >15% asymmetry compared to a mirror homolog in the absence of carotid stenosis or reocclusion.

RESULTS

Regions of no-reflow were identified in 33 of 130 patients (25.3%), encompassed a median of 60.2% (interquartile range 47.8%-70.7%) of the infarct volume, and involved both subcortical (n = 26 of 33, 78.8%) and cortical (n = 10 of 33, 30.3%) regions. Patients with no-reflow had a median 25.2% (interquartile range 16.4%-32.2%, p < 0.00001) relative cerebral blood volume interside reduction and 19.1% (interquartile range 3.9%-28.3%, p = 0.00011) relative cerebral blood flow reduction but similar mean transit time (median -3.3%, interquartile range -11.9% to 24.4%, p = 0.24) within the infarcted region. Baseline characteristics were similar between patients with and those without no-reflow. The presence of no-reflow was associated with hemorrhagic transformation (adjusted odds ratio [aOR] 1.79, 95% confidence interval [CI] 2.32-15.57, p = 0.0002), greater infarct growth (β = 11.00, 95% CI 5.22-16.78, p = 0.00027), reduced NIH Stroke Scale score improvement at 24 hours (β = -4.06, 95% CI 6.78-1.34, p = 0.004) and being dependent or dead at 90 days as assessed by the modified Rankin Scale (aOR 3.72, 95% CI 1.35-10.20, p = 0.011) in multivariable analysis.

DISCUSSION

Cerebral no-reflow in humans is common, can be detected by its characteristic perfusion imaging profile using readily available sequences in the clinical setting, and is associated with posttreatment complications and being dependent or dead. Further studies evaluating the role of no-reflow in secondary injury after angiographic reperfusion are warranted.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that cerebral no-reflow on CT/MRI perfusion imaging at 24 hours is associated with posttreatment complications and poor 3-month functional outcome.

Reduced Severity of Tissue Injury Within the Infarct May Partially Mediate the Benefit of Reperfusion in Ischemic Stroke

BACKGROUND

Emerging data suggest tissue within the infarct lesion is not homogenously damaged following ischemic stroke but has a gradient of injury. Using blood-brain-barrier (BBB) disruption as a marker of tissue injury, we tested whether therapeutic reperfusion improves clinical outcome by reducing the severity of tissue injury within the infarct in patients with ischemic stroke.

METHODS

In a pooled analysis of patients treated for anterior circulation large vessel occlusion in the EXTEND-IA TNK (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke) and EXTEND-IA part-2 (Determining the Optimal Dose of Tenecteplase Before Endovascular Therapy for Ischaemic Stroke) trials, post-treatment BBB permeability at 24 hours was calculated based on the extent of T1-brightening by extravascular gadolinium on T2* perfusion-weighted imaging and measured within the diffusion-weighted-imaging lesion. First, to determine the clinical significance of BBB disruption as a marker of severity of tissue injury, we examined the association between post-treatment BBB permeability and functional outcome. Second, we performed an exploratory (reperfusion, BBB permeability, functional outcome) mediation analysis to estimate the proportion of the reperfusion-outcome relationship that is mediated by change in BBB permeability.

RESULTS

In the 238 patients analyzed, an increased BBB permeability measured within the infarct at 24 hours was associated with a reduced likelihood of favorable outcome (90-day modified Rankin Scale score of ≤2) after adjusting for age, baseline National Institutes of Health Stroke Scale, premorbid modified Rankin Scale, infarct topography, laterality, thrombolytic agent, sex, parenchymal hematoma, and follow-up infarct volume (adjusted odds ratio, 0.86 [95% CI, 0.75-0.98], P=0.023). Mediation analysis suggested reducing the severity of tissue injury (as estimated by BBB permeability) accounts for 18.2% of the association between reperfusion and favorable outcome, as indicated by a reduction in the regression coefficient of reperfusion after addition of BBB permeability as a covariate.

CONCLUSIONS

In patients with ischemic stroke, reduced severity of tissue injury within the infarct, as determined by assessing the integrity of the BBB, is independently associated with improved functional outcome. In addition to reducing diffusion-weighted imaging-defined infarct volume, reperfusion may also improve clinical outcome by reducing tissue injury severity within the infarct.

Abstract 44: Safety Of Tenecteplase And Alteplase In Tandem Lesion Stroke: A Pooled Analysis Of The Extend-IA TNK Trials

Introduction: The efficacy of tenecteplase (TNK) in patients with tandem lesions (TL) in the anterior circulation is unknown. The longer half-life of TNK could potentially lead to increased hemorrhage, especially in patients who require stenting of the extracranial internal carotid artery (eICA) and subsequent antiplatelet therapy. We assessed the efficacy and safety of TNK in a pooled analysis of the EXTEND-IA TNK trials.

Methods: We compared the treatment effect of TNK (pooled analysis of 0.25 and 0.40mg/kg dosing) with alteplase (tPA), stratifying for TL presence. A TL was defined as a combination of eICA pathology (ipsilateral stenosis >70% or occlusion) and intracranial LVO. Outcomes evaluated include 90-day mRS, intracranial reperfusion at initial angiographic assessment, mortality, ICH (symptomatic [sICH] and parenchymal hematoma [PH]). Treatment effect was adjusted for baseline NIHSS, age, and time from symptom onset to puncture via mixed effects proportional odds and logistic regression models.

Results: Of 483 patients with an anterior circulation occlusion, 71/483 (15%) patients had a TL and 43/71 (61%) patients required eICA stenting. In TL patients, reperfusion at initial angiographic assessment was observed in 11/56 (20%) of patients treated with TNK vs. 1/15 (7%) patients treated with tPA (aOR:3.71; 95% CI:0.42-32.75). sICH was observed in 4/71(6%) TL vs 7/412 (2%) nonTL patients (p=0.04). Among TL patients, sICH occurred in 4/56 (7%) patients treated with TNK vs 0/15 (0%) tPA treated patients (p=0.57); sICH occurred in 2/40 (5%) of the 0.25mg/kg TNK group and 2/16 (12.5%) of the 0.40mg/kg TNK group. PH was observed in 6/56 (11%) patients treated with TNK vs 0/15 (0%) tPA treated patients (p=0.33). 90-day mRS (TNK median 2 vs. tPA median 4, acOR:1.21; 95% CI:0.42-3.48), mortality (TNK: 5 [9%] vs. tPA: 3 [20%], aOR:0.45; 95% CI:0.08-2.50), and eICA stenting (TNK: 35 [64%] vs. tPA: 8 [57%], p=0.65) rates did not differ between the two treatment groups.

Conclusions: Although patients with TL in the anterior circulation were at higher risk of hemorrhagic complications, these did not significantly differ between the TNK and tPA groups. A numeric increase in bleeding with TNK was not accompanied by an increase in mortality or worse functional outcome.

Does tranexamic acid affect intraventricular hemorrhage growth in acute ICH? An analysis of the STOP-AUST trial

Background

Trials of tranexamic acid (TXA) in acute intracerebral hemorrhage (ICH) have focused on the imaging outcomes of intraparenchymal hematoma growth. However, intraventricular hemorrhage (IVH) growth is also strongly associated with outcome after ICH. Revised definitions of hematoma expansion incorporating IVH growth have been proposed.

Aims

We sought to evaluate the effect of TXA on IVH growth.

Methods

We analyzed data from the STOP-AUST trial, a prospective randomized trial comparing TXA to placebo in ICH patients presenting ≤ 4.5 h from symptom onset with a CT-angiography spot sign. New IVH development at follow-up, any interval IVH growth, and IVH growth ≥ 1 mL were compared between the treatment groups using logistic regression. The treatment effect of TXA against placebo using conventional (> 6 mL or 33%), and revised definitions of hematoma expansion (> 6 mL or 33% or IVH expansion ≥ 1 mL, > 6 mL or 33%, or any IVH expansion, and > 6 mL or 33% or new IVH development) were also assessed. Treatment effects were adjusted for baseline ICH volume.

Results

The analysis population consisted of 99 patients (50 placebo, 49 TXA). New IVH development at follow-up was observed in 6/49 (12%) who received TXA and 13/50 (26%) who received placebo (aOR: 0.38 [95% CI: 0.13–1.13]). Any interval IVH growth was observed in 12/49 (25%) who received TXA versus 26/50 (32%) receiving placebo (aOR: 0.69 [95% CI: 0.28–1.66]). IVH growth ≥ 1 mL did not differ between the two groups. Using revised definitions of hematoma expansion, no significant difference in treatment effect was observed between TXA and placebo.

Conclusions

IVH may be attenuated by TXA following ICH; however, studies with larger cohorts are required to investigate this further.

Registration

http://www.clinicaltrials.gov ; Unique identifier: NCT01702636.

Spatial Variation of Trace Metals between Industrial and Rural Dwelling Birds of India

A large quantity of trace metals has been continuously polluting the environment as a result of increasing urbanization and industrial processes. In 2016-2017, the metal (Cd, Cu, Cr, Ni, Pb, and Zn) levels were determined in fecal pellets of Blue Rock Pigeon (Columba livia) at Bais Godam (industrial location) in Jaipur and Chittora (rural location) in Rajasthan, India. Fecal pellets in industrial regions which are under higher anthropogenic influence exhibited higher metal concentrations when compared with the fecal pellets of the same species in rural area which have minimal anthropogenic input, with statistically significant industrial-rural differences in the metal concentrations except for Ni. Results obtained in this study, as well as the comparison with literature data, indicated that concentrations of Cr and Cu were high in fecal pellets of Blue Rock Pigeon in the industrial region of the present study. Furthermore, many significant correlations were also observed between metal levels in the industrial region which could be attributed to a similar source. Moreover, contamination levels of pigeon excrement serve as one of the most compelling indicators in terrestrial systems for the monitoring of metal pollution levels.

Tranexamic acid for intracerebral haemorrhage within 2 hours of onset: protocol of a phase II randomised placebo-controlled double-blind multicentre trial

Rationale

Haematoma growth is common early after intracerebral haemorrhage (ICH), and is a key determinant of outcome. Tranexamic acid, a widely available antifibrinolytic agent with an excellent safety profile, may reduce haematoma growth.

Methods and design

Stopping intracerebral haemorrhage with tranexamic acid for hyperacute onset presentation including mobile stroke units (STOP-MSU) is a phase II double-blind, randomised, placebo-controlled, multicentre, international investigator-led clinical trial, conducted within the estimand statistical framework.

Hypothesis

In patients with spontaneous ICH, treatment with tranexamic acid within 2 hours of onset will reduce haematoma expansion compared with placebo.

Sample size estimates

A sample size of 180 patients (90 in each arm) would be required to detect an absolute difference in the primary outcome of 20% (placebo 39% vs treatment 19%) under a two-tailed significance level of 0.05. An adaptive sample size re-estimation based on the outcomes of 144 patients will allow a possible increase to a prespecified maximum of 326 patients.

Intervention

Participants will receive 1 g intravenous tranexamic acid over 10 min, followed by 1 g intravenous tranexamic acid over 8 hours; or matching placebo.

Primary efficacy measure

The primary efficacy measure is the proportion of patients with haematoma growth by 24±6 hours, defined as either ≥33% relative increase or ≥6 mL absolute increase in haematoma volume between baseline and follow-up CT scan.

Discussion

We describe the rationale and protocol of STOP-MSU, a phase II trial of tranexamic acid in patients with ICH within 2 hours from onset, based in participating mobile stroke units and emergency departments.

Does variability in automated perfusion software outputs for acute ischemic stroke matter? Reanalysis of EXTEND perfusion imaging

Aims

We reprocessed the Extending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) perfusion imaging with a different automated software with the aim of comparing mismatch eligibility and outcomes.

Methods

EXTEND baseline perfusion imaging data were reprocessed using autoMIStar software to identify patients who were eligible based on the same target mismatch criteria as per the original trial.

Results

From the 225 patients fulfilling RAPID‐based mismatch criteria randomized in the EXTEND study, 196 (87%) patients met the revised mismatch criteria. Most common reasons for not meeting revised criteria were core >70 ml (n = 9), and no perfusion lesion/lack of penumbral tissue (n = 20). The revised perfusion lesion volumes were significantly smaller compared to the original RAPID volumes (median 68 ml IQR 34–102 ml vs. 42 ml 16–92 ml, p = 0.036). Of the patients who met the revised mismatch criteria, 40% receiving alteplase had modified Rankin Scale (mRS) 0–1 at 3‐month compared to 28% with placebo (Adjusted Odds Ratio (OR) = 2.23, CI 1.08–4.58, p = 0.028). In contrast, in the original mismatch cohort, 35% receiving alteplase had mRS 0–1 at 3‐month compared to 30% with placebo (adjusted OR = 1.88, p = 0.056).

Conclusions

These data reinforce the benefit of alteplase in the later time window, and suggest that differences in automated perfusion imaging software outputs may be clinically relevant.

Association between pre-treatment perfusion profile and cerebral edema after reperfusion therapies in ischemic stroke

The relationship between reperfusion and edema is unclear, with experimental and clinical data yielding conflicting results. We investigated whether the extent of salvageable and irreversibly-injured tissue at baseline influenced the effect of therapeutic reperfusion on cerebral edema. In a pooled analysis of 415 patients with anterior circulation large vessel occlusion from the Tenecteplase-versus-Alteplase-before-Endovascular-Therapy-for-Ischemic-Stroke (EXTEND-IA TNK) part 1 and 2 trials, associations between core and mismatch volume on pre-treatment CT-Perfusion with cerebral edema at 24-hours, and their interactions with reperfusion were tested. Core volume was associated with increased edema (p < 0.001) with no significant interaction with reperfusion (p = 0.82). In comparison, a significant interaction between reperfusion and mismatch volume (p = 0.03) was observed: Mismatch volume was associated with increased edema in the absence of reperfusion (p = 0.009) but not with reperfusion (p = 0.27). When mismatch volume was dichotomized at the median (102 ml), reperfusion was associated with reduced edema in patients with large mismatch volume (p < 0.001) but not with smaller mismatch volume (p = 0.35). The effect of reperfusion on edema may be variable and dependent on the physiological state of the cerebral tissue. In patients with small to moderate ischemic core volume, the benefit of reperfusion in reducing edema is related to penumbral salvage.

What Makes Our Medical Laboratory Workforce Unique?

Introduction/Objective

A career in the medical laboratory requires advanced education and technical training. To assist both employers and employees, several government organizations conduct demographic, education, and wage surveys for the general U.S. labor market. Through its workforce surveys, the American Society of Clinical Pathology (ASCP) does the same for the medical laboratory professions. Our aim was to compare the findings of these surveys and identify similarities and dissimilarities between the general labor pool and the medical laboratory workforce.

Methods/Case Report

Since the 2021 ASCP Wage survey is currently open, we reviewed the findings described in ASCP’s 2019 Wage Survey of Medical Laboratories in the United States (Am J Clin Pathol 2021;155:649-673) with the publicly available information (for 2019) on demographics, educational attainment, and average hourly earnings available on the websites of U.S. Bureau of Labor Statistics (www.bls.gov) as well as United States Census (www.census.gov).

Results (if a Case Study enter NA)

In 2019, the male: female ratio was 52.9:47.1 in general labor pool and 19.1:80.9 in the medical laboratory workforce. The average age of a worker in the general labor pool was 41.9 years and was 42 years in the medical laboratory workforce. The average hourly earnings were $27.99/hour in the general labor pool and ranged from $16.64/hour (phlebotomists) to $53.95/hour (pathologists assistants) in the medical laboratory workforce, with the MLS/MT/CLS earning $30.02/hour to $52.53/hour. While 33.1% adults in the U.S. have attained a bachelor’s degree or above, 73.79% have attained this in the medical laboratory workforce.

Conclusion

Compared to the general labor pool, the medical laboratory workforce is a highly educated workforce and has a higher participation by women. The average worker age and average hourly wage are comparable. We encourage laboratorians to participate in ASCP surveys since such surveys reveal data that can drive better prospects for the medical laboratory workforce.

POC Programs: A Brief Survey on Critical Value Thresholds, Instrumentation, Repeat Testing, and Training Documentation

Introduction/Objective

Across the United States, Point of Care (POC) programs oversee glucometer testing and are often expected to enforce thresholds for critical values, as well as provide guidance on repeat testing. Additionally, POC must track training and ongoing competency assessments of glucometer operators. Our aim was to survey POC across North America to capture the current state of variation in these POC functions, and identify opportunities for standardization.

Methods/Case Report

In July of 2021, an online survey was created on www.surveymonkey.com and distributed via the POC listserv of the American Association for Clinical Chemistry (AACC). The survey listed nine questions regarding instrumentation, threshold levels for critical-high and critical-low, policies on repeat testing, and practices around documentation and record retention.

Results (if a Case Study enter NA)

Of the 63 responses received, almost all (95.2%, n=60) indicated that their institution defines glucometer critical value thresholds. Of these, the most common threshold for critical-high was 400 mg/dL (44.4%, n=28) and for critical-low was 50 mg/dL (39.7%, n=25). A majority (55.5%, n=35) of programs require repeat testing of results that exceeded critical limits. The most popular POC result management software (50.8%, n=32) was RALS (Abbott Diagnostics, Chicago, IL) and the most popular glucometer (56%, n=23) was Roche Accu- Chek Inform II (Roche Diagnostics, Basel, Switzerland). Regarding institutions that disclosed training and competency documentation practices (93.7%, n=59), a majority (57.6%, n=34) used online-only storage, followed by hybrid online- paper storage (32.2%, n=19), and paper-only storage (10.2%, n=6).

Conclusion

Our brief survey has uncovered variations and insights that should raise queries on the feasibility of standardized critical value thresholds, as well as uniform recommendations for retesting critical values. We observed widespread adoption of middleware, as well as online record-keeping. We hope that our findings will trigger further discussions and follow-up studies by other researchers in the POC field.

Optimal Tissue Reperfusion Estimation by Computed Tomography Perfusion Post-Thrombectomy in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Modified Thrombolysis in Cerebral Infarction score (mTICI) ≥2b is defined as successful reperfusion. However, mTICI has rarely been correlated with dynamic perfusion imaging postendovascular therapy for acute stroke. We aimed to study the proportion of tissue optimal reperfusion (TOR) postendovascular therapy across different grades of mTICI.

METHODS

We conducted a single-center retrospective analysis of patients with acute ischemic strokes who had endovascular therapy between 2018 and 2019. Computer tomography perfusion or magnetic resonance perfusion was performed before and after endovascular therapy. Tmax+6 volume reduction of >90% was defined as TOR. Comparisons of proportions of TOR in different grades of mTICI were performed. In the present study, the requirement for informed consents was waived.

RESULTS

Eighty-two patients were included. The difference in the proportion of TOR for TICI categories was statistically significant (mTICI score 0, 0%, mTICI score 2A, 0%, mTICI score 2b, 50.0%, mTICI score 2c, 80.0%, mTICI score 3, 81.3%, χ²=14.035, P=0.003). Multivariable logistic regression showed that lower age (odds ratio, 0.932, P=0.017), onset-to-tissue-type plasminogen activator time (odds ratio, 0.980, P=0.005) and TOR (odds ratio, 8.764, P=0.031) were associated with favorable functional outcome.

CONCLUSIONS

The proportion of TOR achieved by mTICI score of 2b was significantly lower than mTICI score of 2c and mTICI score of 3. TOR was associated with favorable functional outcome, and the degree of reperfusion was more strongly correlated with outcomes than the mTICI scores.

Automated Perfusion-Diffusion Magnetic Resonance Imaging in Childhood Arterial Ischemic Stroke

[Figure: see text].

Structural basis for the binding of the cancer targeting scorpion toxin, ClTx, to the vascular endothelia growth factor receptor neuropilin-1

Chlorotoxin (ClTx) is a 36-residue disulfide-rich peptide isolated from the venom of the scorpion Leiurus quinquestriatus. This peptide has been shown to selectively bind to brain tumours (gliomas), however, with conflicting reports regarding its direct cellular target. Recently, the vascular endothelial growth factor receptor, neuropilin-1 (NRP1) has emerged as a potential target of the peptide. Here, we sought to characterize the details of the binding of ClTx to the b1-domain of NRP1 (NRP1-b1) using solution state nuclear magnetic resonance (NMR) spectroscopy. The 3D structure of the isotope labelled peptide was solved using multidimensional heteronuclear NMR spectroscopy to produce a well-resolved structural ensemble. The structure points to three putative protein-protein interaction interfaces, two basic patches (R14/K15/K23 and R25/K27/R36) and a hydrophobic patch (F6/T7/T8/H10). The NRP1-b1 binding interface of ClTx was elucidated using ¹⁵N chemical shift mapping and included the R25/K27/R36 region of the peptide. The thermodynamics of binding was determined using isothermal titration calorimetry (ITC). In both NMR and ITC measurements, the binding was shown to be competitive with a known NRP1-b1 inhibitor. Finally, combining all of this data we generate a model of the ClTx:NRP1-b1 complex. The data shows that the peptide binds to the same region of NRP1 that is used by the SARS-CoV-2 virus for cell entry, however, via a non-canonical binding mode. Our results provide evidence for a non-standard NRP1 binding motif, while also providing a basis for further engineering of ClTx to generate peptides with improved NRP1 binding for future biomedical applications.

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Structural details of the binding of the scorpion toxin, chlorotoxin (ClTx) to the VEGF receptor neuropilin-1 (NRP1).

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ClTx was produced in its native fold and isotope labelled using a new, high-yield, bacterial expression system.

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Multidimensional heteronuclear NMR experiments reveal the high-resolution structure of ClTx and its binding to NRP1.

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ClTx binds to NRP1 via a non-canonical primary sequence that satisfies the receptor binding motif through its tertiary fold.

Cerebral Edema in Patients With Large Hemispheric Infarct Undergoing Reperfusion Treatment: A HERMES Meta-Analysis

BACKGROUND AND PURPOSE

Whether reperfusion into infarcted tissue exacerbates cerebral edema has treatment implications in patients presenting with extensive irreversible injury. We investigated the effects of endovascular thrombectomy and reperfusion on cerebral edema in patients presenting with radiological evidence of large hemispheric infarction at baseline.

METHODS

In a systematic review and individual patient-level meta-analysis of 7 randomized controlled trials comparing thrombectomy versus medical therapy in anterior circulation ischemic stroke published between January 1, 2010, and May 31, 2017 (Highly Effective Reperfusion Using Multiple Endovascular Devices collaboration), we analyzed the association between thrombectomy and reperfusion with maximal midline shift (MLS) on follow-up imaging as a measure of the space-occupying effect of cerebral edema in patients with large hemispheric infarction on pretreatment imaging, defined as diffusion-magnetic resonance imaging or computed tomography (CT)-perfusion ischemic core 80 to 300 mL or noncontrast CT-Alberta Stroke Program Early CT Score ≤5. Risk of bias was assessed using the Cochrane tool.

RESULTS

Among 1764 patients, 177 presented with large hemispheric infarction. Thrombectomy and reperfusion were associated with functional improvement (thrombectomy common odds ratio =2.30 [95% CI, 1.32-4.00]; reperfusion common odds ratio =4.73 [95% CI, 1.66-13.52]) but not MLS (thrombectomy β=-0.27 [95% CI, -1.52 to 0.98]; reperfusion β=-0.78 [95% CI, -3.07 to 1.50]) when adjusting for age, National Institutes of Health Stroke Score, glucose, and time-to-follow-up imaging. In an exploratory analysis of patients presenting with core volume >130 mL or CT-Alberta Stroke Program Early CT Score ≤3 (n=76), thrombectomy was associated with greater MLS after adjusting for age and National Institutes of Health Stroke Score (β=2.76 [95% CI, 0.33-5.20]) but not functional improvement (odds ratio, 1.71 [95% CI, 0.24-12.08]).

CONCLUSIONS

In patients presenting with large hemispheric infarction, thrombectomy and reperfusion were not associated with MLS, except in the subgroup with very large core volume (>130 mL) in whom thrombectomy was associated with increased MLS due to space-occupying ischemic edema. Mitigating cerebral edema-mediated secondary injury in patients with very large infarcts may further improve outcomes after reperfusion therapies.

Using ultrasound for screening scoliosis to reduce unnecessary radiographic radiation - a prospective diagnostic accuracy study on 442 schoolchildren

Scoliosis screening is important for timely initiation of brace treatment to mitigate curve progression in skeletally immature children. Scoliosis screening programs frequently include the protocol of referring children screened positive with Scoliometer and Moiré Topography for confirmatory standard radiography. Despite being highly sensitive (88%) for detecting those who require specialist referral, the screening program was found to have more than 50% false positive rate that leads to unnecessary radiation exposure. Radiation-free ultrasound has been reported to be reliable for quantitative assessment of scoliosis curves. The aim of this prospective diagnostic accuracy study was to determine the accuracy of ultrasound in determining the referral status for children initially screened positive for scoliosis. 442 schoolchildren with a mean Cobb angle of 14.0 ± 6.6° were recruited. Using x-ray as the gold standard, the sensitivity and specificity of ultrasound in predicting the correct referral status were 92.3% and 51.6% respectively. ROC curve analysis revealed an area under curve of 0.735 for ultrasound alone and 0.832 for ultrasound plus scoliometer measurement. The finding provided strong evidences on the accuracy of ultrasound in determining the referral status that could result in more than 50% reduction of unnecessary radiation exposure for children undergoing scoliosis screening.

Computational insights of phytochemical-driven disruption of RNA-dependent RNA polymerase-mediated replication of coronavirus: a strategic treatment plan against coronavirus disease 2019

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised global health concerns. RNA-dependent RNA polymerase (RdRp) is the prime component of viral replication/proliferation machinery and is considered to be a potential drug target against SARS-CoV-2. The present study investigated the anti-RdRp activity of phytochemicals against SARS-CoV-2 infection. Virtual ligand screening was carried out to determine the potent compounds against RdRp. Molecular docking and an MD Simulation study were employed to evaluate the spatial affinity of selected phytochemicals for the active sites of RdRp. Structural stability of target compounds was determined using root mean square deviation computational analysis and drug-like abilities were investigated using ADMET. Bond distances between ligand and receptor were marked to predict the strength of interaction. Aloe, azadirachtin, columbin, cirsilineol, nimbiol, nimbocinol and sage exhibited the highest binding affinities and interacted with active sites of RdRp, surpassing the ability of chloroquine, lamivudine, favipiravir and remdesivir to target the same. All the natural metabolites exhibited stable conformation during MD Simulation of 101 ns at 310 K. Kinetic, potential and electrostatic energy were observed to be least in the case of natural metabolites in comparison with synthetic analogues. Deviations and fluctuations were observed to be structurally least in target phytochemicals. Physiochemical and biological properties of these compounds further validated their drug-like properties. Non-bonded distance was found to be short enough to form hydrogen bonding or hydrophobic interactions, which revealed that these target compounds can strongly bind with RdRp. The study found potential phytochemicals to disrupt the replication domain of SARS-CoV-2 by hindering RdRp. We therefore anticipate that the current findings could be considered as valuable for the development of an efficient preventive/therapeutic expedient against COVID-19.

From the lecture theatre to your digital device: Reflections on the production of educational podcasts within undergraduate psychiatry training

Introduction

The COVID-19 pandemic has highlighted a need for engaging online resources to enrich psychiatry training for undergraduate medical students. Podcasting is a well-established digital communication platform utilised daily in a myriad of capacities, including education. A group of medical students were tasked with creating their own educational podcasts covering specific aspects of psychiatry.

Objectives

Each pair was set a sub-topic of psychiatry and utilised software to produce educational resources. The objective of this project was to reflect upon production as well as explore the efficacy of podcasting as a tool within undergraduate training.

Methods

The medical students conducted research and contacted experts within the field to contribute to their podcasts. The majority of the students then conducted reviews of the literature surrounding podcasting within medical education, which informed the production of their own podcasts. From this, it was discussed how this project could impact future practice, and indicated that podcasts may become crucial asynchronous learning tools in medical education.

Results

Literature review and first-hand experience of podcast production enabled the students to appreciate the advantages of podcasting and the potential for its widespread future applications. Their wider reading revealed that podcast-using study participants outperformed or matched their peers in assessments, and overwhelmingly enjoyed using podcasts over traditional teaching methods.

Conclusions

The use of podcasting can complement traditional psychiatry training and appeal to a generation of digital natives that prefer this learning style. Podcast production is also an excellent revision method, highlighting the advantages of peer-to-peer education in both learning and increasing engagement with psychiatry.

Disclosure

No significant relationships.

Evaluation of molecular interaction, physicochemical parameters and conserved pattern of SARS-CoV-2 Spike RBD and hACE2: in silico and molecular dynamics approach

OBJECTIVE

Recent pandemic virus SARS-CoV-2 is a global warning for the healthcare system. The spike protein of virus SARS-CoV-2 is significant because of two reasons. Firstly, the spike protein of this virus binds with the human ACE2 (hACE2) receptor. Secondly, it has several antigenic regions that might be targeted for vaccine development. However, the structural analytical data for the spike protein of this virus is not available.

MATERIALS AND METHODS

Here, we performed an analysis to understand the structural two subunits of S glycoprotein (S gp) of SARS-CoV-2. Further, an analysis of secondary structure components and the tertiary structure analysis of RBD was carried out. We also performed molecular interaction analysis between S gp of this virus and hACE2 as well as between SARS-CoV S gp and hACE2 to compare the binding properties of these two viruses.

RESULTS

We noted that the molecular interaction of SARS-CoV-2 S gp and hACE2 form eleven hydrogen bonds, while the molecular interaction of SARS-CoV S gp and hACE2 receptor form seven hydrogen bonds, indicating that the molecular interaction of SARS-CoV-2 S gp and hACE2 receptor is more stable than SARS-CoV S gp and hACE2 receptor. The pairwise sequence alignment of S gp SARS-CoV and SARS-CoV-2 shows several conserved residues of these two proteins. Besides, conserved pattern analysis of SARS-CoV-2 S gp and hACE2 revealed the presence of several highly conserved regions for these two proteins. The molecular dynamics simulation shows a stable interplay between SARS-CoV-2 S gp with the hACE2 receptor.

CONCLUSIONS

The present study might help determine the SARS-CoV-2 virus entrance mechanism into the human cell. Moreover, the understanding of the conserved regions may help in the process of therapeutic development from the infection of the deadly virus.

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.