Risk of Hemorrhagic Transformation with Early Use of Direct Oral Anticoagulants after Acute Ischemic Stroke: A Pooled Analysis of Prospective Studies and Randomized Trials

INTRODUCTION

Precise risk of hemorrhagic transformation (HT) in acute ischemic stroke (AIS) remains unknown, leading to delays in anticoagulation initiation for secondary stroke prevention. We sought to assess the rate of HT associated with direct oral anticoagulant (DOAC) initiation within and beyond 48 hours post-AIS.

METHODS

A pooled analysis of DOAC initiation within 14 days of AIS or transient ischemic attack (TIA) was conducted with 6 studies (4 prospective open label treatment, blinded outcome studies and 2 randomized trials; NCT02295826 and NCT02283294). The primary endpoint was incident radiographic HT on follow-up imaging (day 7-30). Secondary endpoints included symptomatic HT, new parenchymal hemorrhage, recurrent ischemic events, extracranial hemorrhage, study-period mortality, and follow-up modified Rankin Scale score. The results were reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

We evaluated 509 patients; median infarct volume was 1.5 (0.1-7.8) ml, and median National Institutes of Health Stroke Scale was 2 (0-3). Incident radiographic HT was seen on follow-up scan in 34 (6.8%) patients. DOAC initiation within 48 hours from index event was not associated with incident HT (adjusted OR 0.67, [0.30 - 1.50] P=0.32). No patients developed symptomatic HT. Conversely, 31 (6.1%) patients developed recurrent ischemic events, 64% of which occurred within 14 days. Initiating a DOAC within 48 hours of onset was associated with similar recurrent ischemic event rates compared to those in which treatment was delayed (HR 0.42, [0.17 - 1.008] P=0.052). In contrast to HT, recurrent ischemic events were associated with poor functional outcomes (OR=6.8, [2.84 - 16.24], p<0.001).

CONCLUSIONS

In this pooled analysis, initiation of DOAC within 48 hours post-stroke was not associated with increased incident risk of HT, and none developed symptomatic HT. The analysis was underpowered to determine the effect of early DOAC use upon recurrent ischemic events.

Three-month functional outcomes following endovascular thrombectomy during the first wave of the COVID-19 pandemic: a Canadian single-center cohort study

BACKGROUND

The COVID-19 pandemic has disrupted acute stroke care logistics, including delays in hyperacute management and decreased monitoring following endovascular therapy (EVT). We aimed to assess the impact of the pandemic on 90-day functional outcome among patients treated with EVT.

METHODS

This is an observational cohort study including all patients evaluated for an acute stroke between March 30, 2020 and September 30, 2020 (pandemic cohort) and 2019 (reference cohort) in a high-volume Canadian academic stroke center. We collected baseline characteristics, acute reperfusion treatment and management metrics. For EVT-treated patients, we assessed the modified Rankin score (mRS) at 90 days. We evaluated the impact of the pandemic on a 90-day favourable functional status (defined as mRS 0-2) and death using multivariable logistic regressions.

RESULTS

Among 383 and 339 patients included in the pandemic and reference cohorts, baseline characteristics were similar. Delays from symptom onset to evaluation and in-house treatment were longer during the early first wave, but returned to reference values in the subsequent months. Among the 127 and 136 EVT-treated patients in each respective cohort, favourable 90-day outcome occurred in 53/99 (53%) vs 52/109 (48%, p=0.40), whereas 22/99 (22%) and 28/109 (26%, p=0.56) patients died. In multivariable regressions, the pandemic period was not associated with 90-day favourable functional status (aOR 1.27, 95% CI 0.60 to 2.56) or death (aOR 0.74, 95% CI 0.33 to 1.63).

CONCLUSION

In this single-center cohort study conducted in a Canadian pandemic epicenter, the first 6 months of the COVID-19 pandemic did not impact 90-day functional outcomes or death among EVT-treated patients.

Antimicrobial activity of harzianic acid against Staphylococcus pseudintermedius

The emerging concern about the increase of antibiotic resistance has encouraged research efforts to develop effective alternatives to counteract bacterial infections. Herein, we studied a new perspective to therapeutic treatment against Staphylococcus pseudintermedius, an opportunistic pathogen documented as the major cause of skin, ear, and post-operative bacterial infections in dogs and cats. Antimicrobial activity of secondary metabolites produced by selected microbial strains belonging to Trichoderma, Talaromyces, Clonostachys and Coniothyrium fungal genera has been tested against S. pseudintermedius. Several extracts, particularly those obtained from Trichoderma harzianum E45 and ET45, showed a significant antimicrobial activity towards S. pseudintermedius methicillin-resistant (MRSP) and methicillin-susceptible (MSSP) strains. Bioassay-guided fractionation of E45 and ET45 extracts allowed to isolate harzianic acid as the major compound responsible for biological activities (e.g. antimicrobial, antibiofilm formation and biofilm disaggregation).

Exophthalmos following mechanical thrombectomy for anterior circulation stroke: A retrospective study and review of literature

BACKGROUND

Anecdotal cases of exophthalmos after acute mechanical thrombectomy have been described. We sought to estimate the incidence in a large cohort of patients with acute anterior circulation stroke treated with mechanical thrombectomy. Secondarily, we aimed to evaluate the underlying mechanism and to differentiate it on imaging from other pathology with similar clinical orbital features.

METHODS

Between November 2016 and November 2018, we performed a retrospective single-center study of 250 patients who underwent anterior circulation mechanical thrombectomy. Development of exophthalmos was independently evaluated by two readers on preprocedure and 24-h postprocedure non-contrast cerebral CT.

RESULTS

In the mechanical thrombectomy cohort, six individuals (2.4%) developed interval ipsilateral exophthalmos at 24 h. Of these, at least two patients developed clinical symptoms. There was almost perfect agreement between assessments of the two readers (Cohen's kappa = 0.907 (95% confidence interval: 0.726, 1.000)). In two patients, there was delayed ophthalmic artery filling on digital subtraction angiography. None of the patients had features of a direct carotid-cavernous fistula.

CONCLUSIONS

Exophthalmos is not uncommon after mechanical thrombectomy (2.4%). The underlying mechanism is difficult to confirm, but it is most likely due to orbital ischemia from hypoperfusion or distal emboli.

Fractional Quantum Hall Effect in Weyl Semimetals

Weyl semimetal may be thought of as a gapless topological phase protected by the chiral anomaly, where the symmetries involved in the anomaly are the U(1) charge conservation and the crystal translational symmetry. The absence of a band gap in a weakly interacting Weyl semimetal is mandated by the electronic structure topology and is guaranteed as long as the symmetries and the anomaly are intact. The nontrivial topology also manifests in the Fermi arc surface states and topological response, in particular taking the form of an anomalous Hall effect in magnetic Weyl semimetals, whose magnitude is only determined by the location of the Weyl nodes in the Brillouin zone. Here we consider the situation when the interactions are not weak and ask whether it is possible to open a gap in a magnetic Weyl semimetal while preserving its nontrivial electronic structure topology along with the translational and the charge conservation symmetries. Surprisingly, the answer turns out to be yes. The resulting topologically ordered state provides a nontrivial realization of the fractional quantum Hall effect in three spatial dimensions in the absence of an external magnetic field, which cannot be viewed as a stack of two dimensional states. Our state contains loop excitations with nontrivial braiding statistics when linked with lattice dislocations.

A randomized pragmatic care trial on endovascular acute stroke interventions (EASI): criticisms, responses, and ethics of integrating research and clinical care

BACKGROUND

The Endovascular Acute Stroke Intervention (EASI) trial was conceived as a pragmatic care trial, designed to integrate trial methods with clinical practice. Reporting the EASI experience was met with objections and criticisms during peer review concerning both scientific and ethical issues. Our goal is to discuss these criticisms in order to promote the pragmatic approach of care trials in outcome-based medical care.

METHODS

The comments and criticisms of 11 reviewers from 5 journals were collected and analyzed. The EASI protocol was also compared to the protocols of seven thrombectomy trials using the pragmatic-explanatory continuum indicator summary (PRECIS).

RESULTS

Main criticisms of EASI concerned selection criteria that were judged to be too vague and too inclusive, brain and vascular imaging methods that were not sufficiently prescribed by protocol, lack of blinding of outcome assessment, and lack of power. EASI was at the pragmatic end of the spectrum of thrombectomy trials.

CONCLUSION

The pragmatic care trial methodology is not currently well-established. More work needs to be done to integrate scientific methods and ethical care in the best medical interest of current patients.

Trichoderma-Based Biostimulants Modulate Rhizosphere Microbial Populations and Improve N Uptake Efficiency, Yield, and Nutritional Quality of Leafy Vegetables

Microbial inoculants such as Trichoderma-based products are receiving great interest among researchers and agricultural producers for their potential to improve crop productivity, nutritional quality as well as resistance to plant pathogens/pests and numerous environmental stresses. Two greenhouse experiments were conducted to assess the effects of Trichoderma-based biostimulants under suboptimal, optimal and supraoptimal levels of nitrogen (N) fertilization in two leafy vegetables: Iceberg lettuce (Lactuca sativa L.) and rocket (Eruca sativa Mill.). The yield, nutritional characteristics, N uptake and mineral composition were analyzed for each vegetable crop after inoculation with Trichoderma strains T. virens (GV41) or T. harzianum (T22), and results were compared to non-inoculated plants. In addition, the effect of the Trichoderma-based biostimulants on microbes associated with the rhizosphere in terms of prokaryotic and eukaryotic composition and concentration using DGGE was also evaluated. Trichoderma-based biostimulants, in particular GV41, positively increased lettuce and rocket yield in the unfertilized plots. The highest marketable lettuce fresh yield was recorded with either of the biostimulant inoculations when plants were supplied with optimal levels of N. The inoculation of rocket with GV41, and to a lesser degree with T22, elicited an increase in total ascorbic acid under both optimal and high N conditions. T. virens GV41 increased N-use efficiency of lettuce, and favored the uptake of native N present in the soil of both lettuce and rocket. The positive effect of biostimulants on nutrient uptake and crop growth was species-dependent, being more marked with lettuce. The best biostimulation effects from the Trichoderma treatments were observed in both crops when grown under low N availability. The Trichoderma inoculation strongly influenced the composition of eukaryotic populations in the rhizosphere, in particularly exerting different effects with low N levels in comparison to the N fertilized plots. Overall, inoculations with Trichoderma may be considered as a viable strategy to manage the nutrient content of leafy horticulture crops cultivated in low fertility soils, and assist vegetable growers in reducing the use of synthetic fertilizers, developing sustainable management practices to optimize N use efficiency.

Abstract WMP9: Real-World Outcomes of Patients Presenting with Acute Ischemic Stroke >6 Hours Since Symptom Onset Treated With Endovascular Therapy

Introduction: Endovascular therapy(EVT) is proven effective for patients with acute ischemic stroke with proximal vessel occlusion, treated within 6 hours since symptom onset. However, up to 30% of stroke patients wake up with their symptoms (“wake-up stroke” (WUS)) or have an unknown time of onset. Canadian guidelines suggest that EVT may also be effective up to 12 hours after onset and yet-to-be published data from the DAWN trial also suggest a strong benefit of EVT for these patients if selected by perfusion imaging. We aimed to examine the real-world effectiveness of EVT in late-presenting stroke patients selected for EVT with a simple non-contrast CT (NCCT) and simple phase CT angiogram (CTA).

Methods: We analyzed a prospectively collected registry of epidemiological, clinical and imaging data of patients treated for acute ischemic stroke ≥6 hours since symptom onset or WUS in a tertiary stroke center (Hôpital Notre-Dame, Montréal) between 2016 and 2017. Eligibility for EVT was based on a combination of disabling neurological deficit, a NCCT with salvageable brain tissue (ASPECTS >5), and presence of a LVO on CTA.

Results: Over a 16-month period, a total of 366 patients were treated with IV thrombolysis and/or EVT. Of these, 46 had WUS or presented ≥ 6 hours since symptom onset and received EVT. Median age was 70, median baseline mRS score 1, median NIHSS at arrival 17 and median ASPECTS 9. Good collaterals on CTA were noted in 63%(29) of patients. 5 patients had posterior circulation stroke with basilar occlusion. Median time from last time seen normal to admission was 9h17(IQR, 6h44-12h46). 31 (67.4%) NCCTs were done at a referent center and not repeated locally to avoid treatment delays. At 3-month follow-up, functional autonomy(mRS ≤ 2) was found in 15 (32.6%) patients while 15 (32,6%) died (mRS=6). Symptomatic hemorrhagic transformation occurred in 3(6.5%) patients.

Conclusions: In a real-world setting, EVT is feasible in late-presenting stroke patients selected by NCCT and yields favorable outcomes similar to those seen in the more pragmatic EVT trials.

Abstract WP339: Arterial Spin Labelling Cerebral Perfusion Measurements Demonstrate Normal Blood Flow in Subacute Intracerebral Hemorrhage Patients

Introduction: Perihematomal hypoperfusion in acute intracerebral hemorrhage (ICH) has been demonstrated using CT perfusion. Although blood pressure (BP) reduction does not appear to impact perihematomal Cerebral Blood Flow (CBF), measurements using contrast are limited to a single time point. It has also been shown that up to 41% of ICH patients develop subacute diffusion-weighted imaging (DWI) lesions on MRI. Arterial Spin Labelling (ASL) is an magnetic resonance imaging (MRI) technique that allows measurement of CBF without a contrast agent, making it suitable for serial measurements. We assessed CBF in ICH patients using ASL and tested the hypothesis that perihematoma perfusion is related to BP.

Methods: Patients with CT scan confirmed ICH were prospectively recruited within 6 hours of symptom onset. Acute systolic BP (SBP) targets were randomly assigned as part of an ongoing trial. The SBP target remained blinded for this analysis. Patients were assessed with ASL at 48 hours post ICH. The perihematoma region was defined using co-registered susceptibility weighted images to delineate the hematoma border. Relative CBF (rCBF) was calculated as a ratio of the ipsilateral to contralateral ASL measurements.

Results: Perfusion was measured in 6 ICH patients, none of whom had DWI lesions, 55.38 (43.72, 59.75) hours after onset. Median 48 hour hematoma volume was 23.40 (18.10, 99.90) ml. Mean±SD SBP at 48 hours was 140.20 ± 10.64 mmHg. Mean perihematomal rCBF was 0.95±0.37. Mean hemispheric rCBF was 0.95 ± 0.17. Perihematomal and hemispheric CBF was not lower in the side of the hematoma ( p >0.583). Hematoma size was unrelated to rCBF (perihematomal R=0.039, 95% CI [-0.880, 0.959], p =0.682; hemispheric R=0.00, 95% CI [-0.005, 0.006], p =0.932). Systolic BP at the time of the scan, difference between baseline SBP and SBP at the time of the scan, and time spent with SBP <140 mmHg were all not associated with perihematomal or hemispheric rCBF ( p >0.170).

Conclusion: It is feasible to measure perihematoma and hemispheric perfusion in ICH patients using ASL, which may be useful for serial CBF assessment, particularly in patients with MRI evidence of ischemia.

Abstract WMP104: Sub-Acute Diffusion-Weighted MRI Lesions in Acute Intracerebral Hemorrhage Patients are Unrelated to Blood Pressure

Introduction: Diffusion-Weighted magnetic resonance imaging (DWI) studies have demonstrated sub-acute ischemic lesions in up to 41% of patients with intracerebral hemorrhage (ICH). Retrospective studies indicated an association with acute blood pressure (BP) reduction. We conducted a prospective study of DWI lesion incidence in ICH patients.

Methods: Patients with computed tomography (CT) scan confirmed ICH were prospectively recruited within 6 hours of symptom onset. Acute systolic BP (SBP) targets were randomly assigned as part of an ongoing trial. The SBP target remained blinded for this analysis. Patients were assessed with serial DWI at 48 hours.

Results: Eighty-three patients (48.2% male, mean±SD age 71.9±13.4) were enrolled. MRI was obtained in 42 patients. (11 patients were medically unstable, 11 refused consent, 19 died or were treated palliatively prior to the first MRI). Median (IQR) acute hematoma volume of the patients undergoing magnetic resonance imaging was 14.11 (4.40, 38.06) ml. Median baseline NIHSS score was 12.50 (9, 20). Median (IQR) 48 hour hematoma volume was 23.30 (9.10, 65.30) ml. DWI lesions were present in 13 (31%) of patients at 48 hours (median time to scan 54.22 (39.83, 65.5) hours). Mean SBP at 48 hours in patients with lesions (154.55±27.02 mmHg) was similar to those without (149.04±27.02; p = 0.514). Systolic BP at the time of the MRI was not a predictor of ischemic lesion development at 48 hours (OR=1.015, [0.972, 1.059], p =0.507), nor was the change in BP between baseline and the scan (OR=0.994, [0.962, 1.027], p =0.716). The only predictor of 48 hour DWI incidence was hematoma volume at 48 hours (OR= 1.025, 95% CI [1.001, 1.050], p =0.044).

Discussion: When enrolled prospectively within 6 hours of onset, DWI was obtained in approximately half of all ICH patients. This selection bias may be relevant to the results of both retrospective and prospective DWI studies. This study demonstrated no evidence of a relationship between actual BP achieved and DWI incidence after ICH.

Canadian stroke best practice recommendations: Secondary prevention of stroke, sixth edition practice guidelines, update 2017

The 2017 update of The Canadian Stroke Best Practice Recommendations for the Secondary Prevention of Stroke is a collection of current evidence-based recommendations intended for use by clinicians across a wide range of settings. The goal is to provide guidance for the prevention of ischemic stroke recurrence through the identification and management of modifiable vascular risk factors. Recommendations include those related to diagnostic testing, diet and lifestyle, smoking, hypertension, hyperlipidemia, diabetes, antiplatelet and anticoagulant therapies, carotid artery disease, atrial fibrillation, and other cardiac conditions. Notable changes in this sixth edition include the development of core elements for delivering secondary stroke prevention services, the addition of a section on cervical artery dissection, new recommendations regarding the management of patent foramen ovale, and the removal of the recommendations on management of sleep apnea. The Canadian Stroke Best Practice Recommendations include a range of supporting materials such as implementation resources to facilitate the adoption of evidence to practice, and related performance measures to enable monitoring of uptake and effectiveness of the recommendations. The guidelines further emphasize the need for a systems approach to stroke care, involving an interprofessional team, with access to specialists regardless of patient location, and the need to overcome geographic barriers to ensure equity in access within a universal health care system.

Dabigatran following acute transient ischemic attack and minor stroke II (DATAS II)

Rationale

Patients with transient ischemic attack or minor stroke are at high risk of early recurrent cerebrovascular events. Anticoagulation with heparin or warfarin acutely after ischemic stroke is at least as efficacious as aspirin for preventing recurrent events but is associated with an increased risk of clinical worsening due to hemorrhagic transformation.

Aim and hypothesis

We aim to demonstrate the safety of early anticoagulation with dabigatran, an oral direct thrombin inhibitor, in acute cerebrovascular syndrome patients. The primary hypothesis is that symptomatic hemorrhagic transformation rates in dabigatran and aspirin-treated patients will be similar.

Sample size estimates

At least 136 participants in two groups required to demonstrate an absolute between-group difference in the rate of hemorrhagic transformation of 5.6% with 80% power, assuming alpha = 5%.

Methods and design

A randomized, multicenter open-label clinical trial (NCT02295826). Three-hundred participants with a transient ischemic attack/ischemic stroke (National Institutes of Health Stroke Scale ≤ 9) will undergo magnetic resonance imaging within 72 h of symptom onset and will be randomized to aspirin 81 mg daily or dabigatran 150 mg twice daily for 30 days. Participants undergo repeat magnetic resonance imaging at 30 days and clinical assessment to 90 days.

Study outcomes

The primary outcome is the symptomatic hemorrhagic transformation rate. Secondary outcomes include recurrent stroke and new ischemic lesions on repeat magnetic resonance imaging.

Discussion

This study will determine the safety of early anticoagulation with dabigatran in patients with acute transient ischemic attack/ischemic stroke and will inform the design of a phase III randomized trial aimed at demonstrating reduced recurrent early ischemic events after acute transient ischemic attack/stroke.

The intracerebral hemorrhage acutely decreasing arterial pressure trial II (ICH ADAPT II) protocol

Background

Aggressively lowering blood pressure (BP) in acute intracerebral hemorrhage (ICH) may improve outcome. Although there is no evidence that BP reduction changes cerebral blood flow, retrospective magnetic resonance imaging (MRI) studies have demonstrated sub-acute ischemic lesions in ICH patients. The primary aim of this study is to assess ischemic lesion development in patients randomized to two different BP treatment strategies. We hypothesize aggressive BP reduction is not associated with ischemic injury after ICH.

Methods

The Intracerebral Hemorrhage Acutely Decreasing Blood Pressure Trial II (ICH ADAPT II) is a phase II multi-centre randomized open-label, blinded-endpoint trial. Acute ICH patients (N = 270) are randomized to a systolic blood pressure (SBP) target of <140 or <180 mmHg. Acute ICH patients within 6 h of onset and two SBP measurements ≥140 mmHg recorded >2 mins apart qualify. SBP is managed with a pre-defined treatment protocol. Patients undergo MRI at 48 h, Days 7 and 30, with clinical assessment at Day 30 and 90. The primary outcome is diffusion weighted imaging (DWI) lesion frequency at 48 h. Secondary outcomes include cumulative DWI lesion rate frequency within 30 days, absolute hematoma growth, prediction of DWI lesion incidence, 30-day mortality rates, day 90 functional outcome, and cognitive status.

Discussion

This trial will assess the impact of hypertensive therapies on physiological markers of ischemic injury. The findings of this study will provide evidence for the link, or lack thereof, between BP reduction and ischemic injury in ICH patients.

Trial registration

This study is registered with clinicaltrials.gov  (NCT02281838, first received October 29, 2014).

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-017-0884-4) contains supplementary material, which is available to authorized users.

Giant reed growth and effects on soil biological fertility in assisted phytoremediation of an industrial polluted soil

Phytoremediation is a cost-effective "green technology" that uses plants to improve the soil properties of polluted sites, preventing the dispersion of pollutants and reducing the mobility of potentially toxic elements (PTEs) through their adsorption and accumulation by roots or precipitation within the root zone. Being highly tolerant to pollutants and other abiotic stresses, giant reed (Arundo donax L.) is a suitable biomass crop for phytoremediation of contaminated soils. We report the results of a two-year open-air lysimeter study aimed at assessing the adaptability of giant reed to grow on industrial substrates polluted by Pb and Zn and at testing commercial humic acids from leonardite as improvers of plant performance. We evaluated giant reed potential for: 1) biomass production for energy or biomaterial recovery; 2) PTE phytoextraction and 3) soil fertility restoration. Chemical fertility was monitored by measuring soil C while soil biological fertility was estimated by quantifying the abundance of bacterial functional genes regulating nitrogen fixation (nifH) and nitrification (amoA). Giant reed above-ground growth on the polluted soils was slightly lower (-16%) than on a non-polluted soil, with a preferential storage of biomass in the rhizome acting as a survival strategy in limiting growing conditions. Humic acids improved plant stress tolerance and production levels. As aerial biomass (shoots) did not accumulate PTEs, the plant in question can be used for bioenergy or biopolymer production. In contrast, below-ground biomass (rhizomes) accumulated PTEs, and can thus be harvested and removed from soil to improve phytoremediation protocols and also used as industrial biofuel. Giant reed growth increased the abundance of N-cycling bacteria and soil C in the rhizospheric soil, as well as reduced soil Pb and Zn EDTA extractable fraction.

Abstract TP373: Tracts Enfolded by Small Hematomas Remain Intact in Acute Intracerebral Hemorrhage

Background: Mortality can be predicted by intracerebral hemorrhage (ICH) volume, but motor recovery in survivors is variable. Motor impairment is likely related to the spatial relationship between the hematoma and corticospinal tract (CST). Diffusion Tensor Imaging (DTI) tractography can be used to visualize white matter tracts in three dimensions. We hypothesized that the interaction between the hematoma and CST would predict motor impairment in ICH patients.

Methods: ICH patients with small-moderate hematomas were prospectively imaged with CT and DTI within 14 days of onset. Hematoma volume was assessed on CT using planimetric techniques. Three-dimensional recreations of the ipsilateral CST and the hematoma were made for each patient. The CST was categorized by interaction with the ICH as CST: Unaffected, Displaced, Partially Severed, Completely Severed, and Splitting the ICH. Motor function was classified as 'good' (NIHSS motor subscale 0-2) or 'poor' (3-8).

Results: Thirty patients (mean age 68±13) underwent CT at a median (IQR) of 2.3 (3.5)h and DTI at 2.0 (3.6, range 0.6-13) days. Median hematoma volume was 8.2 (23) ml.

Lesion distribution was: lobar 11 (37%), basal ganglia 18 (60%), brainstem 1 (3%). CSTs were primarily Displaced (n=9) or Unaffected (8), with the remainder being Partially Severed (4), Completely Severed (5), and Splitting the ICH (4). The latter 4 (13%) patients had small (<6ml, median 2.5 [3.0] ml) basal ganglia bleeds which enfolded the intact CST.

Motor score at Day 7 was good in 50% of patients. Good outcome was seen in 8 (100%) Unaffected, 4 (44%) Displaced, 1 (25%) Partially Severed, 0 (0%) Severed and 2 (50%) Splitting the ICH patients. Logistic regression indicated that good motor score was predicted by CST category (r=2.3, p=0.016).

Conclusion: CST integrity can be maintained when enfolded by small basal ganglia bleeds. Diffusion tractography patterns may be useful for predicting motor scores in small to moderate-sized hematomas.

Abstract 214: Corticospinal Tract Integrity is Acutely Maintained Within Perihematoma Edema

Background: Perihematoma edema in intracerebral hemorrhage (ICH) is thought to be associated with tissue injury. Fractional Anisotropy (FA), as measured with Diffusion Tensor Imaging (DTI), can be used to assess white matter integrity. We tested the hypotheses that sections of the Corticospinal Tract (CST) passing directly through edema would 1) have low FA relative to the entire tract and 2) predict motor score in ICH patients.

Methods: Patients were prospectively imaged with DTI within 14 days of symptom onset. Hematoma volume was measured on CT using planimetric techniques. Edema volume was assessed on CT using a 5-23 Hounsfield Unit threshold. Mean FA was measured in the edematous region (‘perihematoma edema'), the entire ipsilateral CST, and in the portion of CST passing through the perihematoma edema ('edematous CST'). Motor function was evaluated with a composite of the upper and lower extremity NIHSS motor score (0=normal, 8=hemiplegia).

Results: Patients (n=27, mean age 67±13) were scanned with DTI at a median of 2 (3) days. Hematoma distribution was: lobar 5 (18%), basal ganglia 21 (78%), and brainstem 1 (4%). Median acute ICH volume was 8.2 (22) ml at 2 (2)h. Acute edema volume was 0.9 (1.8) ml and grew to 1.9 (3.9) ml at 26h (26). NIHSS motor score was 3 (6) at 72h and 3 (7) at day 7.

FA in the edema was significantly lower (0.23±0.06) than in contralateral mirror regions (0.37 ±0.07, p<0.0001). Mean FA in the edematous CST was lower (0.34±0.08) than FA in the entire ipsilateral CST (0.44±0.04, p<0.0001), but higher than FA in the perihematoma edema (0.25±0.06, p<0.0001).

There was a weak correlation between FA in the edematous CST and 72h motor score (r= -0.40, p=0.050,) which disappeared at day 7 (r= -0.34, p=0.131). FA in the edematous CST was not related to time to scan (r=-0.027, p=0.892).

Hematoma volume predicted FA in the edematous CST (ß=-0.46, 95% CI:[-0.05- -0.01]; p=0.015). Perihematoma edema volume did not predict FA in the edematous CST independently of the ICH (ß=-0.29, [-0.1-0.04]; p=0.475).

Conclusion: FA is decreased in the CST where it passes through the edema, though not to the extent of the surrounding edema. The transient relationship between decreased FA and motor function suggests that edema temporarily impairs tract function but not integrity.

Dabigatran Therapy in Acute Ischemic Stroke Patients Without Atrial Fibrillation

Background and Purpose—

Acute ischemic stroke patients are at risk of early recurrence. We tested the feasibility and safety of initiating dabigatran in patients, within 24 hours of minor stroke in patients without atrial fibrillation.

Methods—

Minor stroke patients (National Institutes of Health Stroke Scale score ≤3) without atrial fibrillation and evidence of acute infarction on magnetic resonance imaging were treated with dabigatran. Treatment began within 24 hours of onset and was continued for 30 days. The primary end point was symptomatic hemorrhagic transformation.

Results—

A total of 53 patients with median (interquartile range) age of 68 (57–77) years and National Institutes of Health Stroke Scale score of 1 (0–2) were enrolled. Baseline diffusion-weighted imaging volume was 0.8 (0.3–2.4) mL. No patients experienced symptomatic hemorrhagic transformation. Three patients had evidence of asymptomatic petechial hemorrhagic transformation on day 7, which remained stable at day 30, while continuing dabigatran.

Conclusions—

Dabigatran treatment within 24 hours of minor stroke is feasible. A larger randomized trial is required to confirm the safety and efficacy of this treatment approach.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT 01769703.

Reduction of Diffusion-Weighted Imaging Contrast of Acute Ischemic Stroke at Short Diffusion Times

Background and Purpose—

Diffusion-weighted imaging (DWI) of tissue water is a sensitive and specific indicator of acute brain ischemia, where reductions of the diffusion of tissue water are observed acutely in the stroke lesion core. Although these diffusion changes have been long attributed to cell swelling, the precise nature of the biophysical mechanisms remains uncertain.

Methods—

The potential cause of diffusion reductions after stroke was investigated using an advanced DWI technique, oscillating gradient spin-echo DWI, that enables much shorter diffusion times and can improve specificity for alterations of structure at the micron level.

Results—

Diffusion measurements in the white matter lesions of patients with acute ischemic stroke were reduced by only 8% using oscillating gradient spin-echo DWI, in contrast to a 37% decrease using standard DWI. Neurite beading has recently been proposed as a mechanism for the diffusion changes after ischemic stroke with some ex vivo evidence. To explore whether beading could cause such differential results, simulations of beaded cylinders and axonal swelling were performed, yielding good agreement with experiment.

Conclusions—

Short diffusion times result in dramatically reduced diffusion contrast of human stroke. Simulations implicate a combination of neuronal beading and axonal swelling as the key structural changes leading to the reduced apparent diffusion coefficient after stroke.

Dynamic Evolution of Diffusion-Weighted Imaging Lesions in Patients With Minor Ischemic Stroke

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) lesion volume on magnetic resonance imaging is increasingly being used as a surrogate outcome measure in clinical trials. We aimed to characterize the evolution of DWI lesion volumes within 30 days of symptom onset after minor stroke.

METHODS

Minor stroke patients with DWI lesions on magnetic resonance imaging within 48 hours of symptom onset were prospectively followed with magnetic resonance imaging brain scan at 7 and 30 days. Change in the lesion volume was defined as the difference between day 30 Fluid-Attenuated Inversion Recovery and baseline DWI lesion volumes.

RESULTS

Three patterns of infarct evolution were observed: reduction (72 [63%]), no change (26 [23%]), and growth (16 [14%]). Patients with infarct reduction at 30 days had larger baseline DWI lesion volumes (2.5 [0.9-8.5] mL) than those with stable infarcts (0.5 [0.3-0.9] mL; P=0.01). Complete DWI reversal at day 30, was seen in only 6 (5.3%) patients.

CONCLUSIONS

The most common pattern of infarct evolution in patients with minor stroke is a reduction in volume, but complete resolution is uncommon.

Abstract W P60: Blood Pressure Reduction In Acute Ischemic Stroke Does Not Affect Ischemic Core Tissue Perfusion

Introduction: Blood pressure (BP) reduction in acute ischemic stroke patients can potentially decrease cerebral blood flow (CBF) in ischemic tissue due to disrupted autoregulation, particularly in the ischemic core. We tested this hypothesis using a 3 group non-randomized controlled study of serial CBF measurements in ischemic stroke patients.

Methods: Patients with acute ischemic stroke ≤72h of symptom onset were recruited. Groups were assigned according to baseline mean arterial blood pressure (MAP): patients with MAP >120mmHg were treated with intravenous labetalol and sublingual (SL) nitroglycerin and those with MAP 100-120 mmHg were treated with SL nitroglycerin. The BP reduction target was 10% of the baseline MAP. Patients with MAP<100 mmHg formed the control group. Patients underwent MR perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) before and after BP reduction. Blinded planimetric assessment was done to determine PWI deficits and DWI lesion volumes in the ischemic core region.

Results: A total of 48 patients with mean±SD age of 65.4±13.2 years were enrolled at 23.4±15.3h after symptom onset. The mean time difference between perfusion scans was 25.6±9.5 min.Median(IQR) DWI volume was 11.1 (96.8) ml. Mean MAP was 126±7.5 mmHg in the MAP>120 group(n=13), 109.9±4.9 mmHg in the MAP 100-120 group (n=16), and 89.9±6.2 mmHg in the controls (n=19). Mean BP reduction in the treated patients was 11.9±6.7 mmHg (95% CI 15.6-3; p=0.04). Baseline mean relative CBF (rCBF) in ischemic core tissue was 1.1±0.47 in the MAP >120 group, 0.87±0.35 in the MAP 100-120 group and 0.78±0.32 in controls. The mean change in rCBF following BP reduction did not differ between the MAP >120 group (0.03±0.17), MAP 100-120 group (0.06±0.17) and controls (0.08±0.25) (p=0.28). Similarly, there was no difference in the mean relative cerebral blood volume (p=0.3) and relative mean transit time (p=0.58) before and after BP reduction. In patients treated with SL nitroglycerin (n=17), there was no improvement in mean lesional rCBF (0.04±0.17 vs.-0.02±0.18, p=0.25).

Conclusion: Modest BP reduction does not lead to an immediate decrease in CBF, within the ischemic core. Acute antihypertensive therapy may be less directly harmful than has been postulated.

Abstract W P306: Novel Oral Anticoagulant Initiation Within 14 days of Stroke Is Not Associated with Excess Hemorrhagic Transformation Rates

Introduction: The risk of early recurrent stroke after a cerebrovascular event is elevated. Despite a lack of safety data related to oral anticoagulation (OAC) after TIA/stroke in patients with atrial fibrillation (AF), particularly with respect to novel OACs (NOACs), many physicians do initiate therapy within 14 days of symptom onset. We aimed to assess current practice patterns and hemorrhagic transformation rates associated with early OAC use in AF patients. Methods: We conducted a retrospective chart review of AF patients admitted to a single stroke unit over a 24-month period. OAC agents and time from onset to initiation were recorded. Hemorrhagic transformation (HT) was assessed on CT scans and graded using the ECASS classification system (Hemorrhagic Infarction; HI and Parenchymal Hemorrhage; PH). Results: A total of 402 AF patients, with a mean age of 78.0±11.4 years (196 female), were included. OACs were initiated in 233 (58.0%) patients within 14 days of symptom onset. Of these 233 patients, warfarin was started in 136 (58.4%), dabigatran in 52 (22.3%), rivaroxaban in 40 (17.2%), and apixaban in 5 (2.1%). The median(IQR) number of days from onset to OAC initiation was similar between patients treated with warfarin (2.0(6.0)), dabigatran (2.0(3.8)), rivaroxaban (3.0(6.8)), and apixaban (3.0(5.5), P=0.44). HT was found in 10 patients, 7 (5.1%) of whom were initiated on warfarin and 3 (5.8%) on dabigatran (λ2= 2.9, P=0.14). Of the 7 warfarin related HT cases, 6 were asymptomatic HI and 1 was a symptomatic PH. All 3 dabigatran related HT cases were asymptomatic HI. HT was detected at a median of 3(4) days following OAC initiation. Systemic bleeding was seen in 7 patients, all of whom were taking warfarin (4 gastrointestinal bleeds, 2 retroperitoneal, and 1 ureteral hematoma). Conclusion: Off-label use of NOACs in acute stroke is common. Although hemorrhagic transformation rates appear to be no higher than those associated with warfarin, early NOAC initiation after stroke should be studied in a prospective fashion.

Abstract W MP112: Hematoma Contraction In Primary Intracerebral Hemorrhage Is Associated With Short-term Functional Outcome

Introduction: Although blood clot retraction is a normal part of wound healing, this process has never been documented in intracerebral hemorrhage (ICH). Using a serial imaging approach, we aimed to assess the frequency of hematoma contraction in ICH patients. We also tested the hypothesis that hematoma contraction is associated with increased perihematoma edema volumes.

Methods: We conducted a retrospective imaging study in primary ICH patients with a non-contrast CT (NCCT) study within 24h of symptom onset. All patients had a follow-up NCCT within 48h of the baseline scan. Patients who underwent any surgical intervention were excluded. Two blinded assessors, planimetrically measured hematoma and perihematoma edema volumes. Hematoma contraction was defined a priori as ≥10% reduction in ICH volume from baseline.

Results: A total of 202 patients with a mean±SD age of 67.9±15.1 years were included. The mean baseline ICH volume was 22.5±23.8ml. The mean difference in ICH volume between the two raters was 0.2±0.8ml (Intraclass correlation coefficient-0.93; 95% Limits of Agreement=0.82-0.95). Hematoma contraction of at least 10% from baseline was seen in 22 (10.9%) patients. The mean absolute change in volume in these patients was -3.9±4.2ml. Hematoma expansion occurred in 51 (25.2%) patients. There is no difference in mean interscan interval between patients with ICH contraction (26.1±11.7h), expansion (20.7±11.8h) or stability (24.2±10.6h, p=0.96). Baseline perihematoma edema volumes were larger in patients with subsequent hematoma contraction (8.9±9.7ml) than those with stable (2.6±2.8 ml) or expanding ICH (3.5±4.4 ml, p<0.0001). Perihematoma edema volume growth was greater in patients with hematoma expansion (7.8±12.11ml) than those with contracting (3.4±4.7ml), or stable ICH (1.6±3.2ml, p=0.004). Median (IQR) modified Rankin scale scores were lower in patients with hematoma contraction (3(2)) or stable hematomas (3(3)) than those with expansion (6(2), p<0.0001).

Conclusions: Hematoma contraction is evident in approximately 10% of ICH patients. Baseline perihematoma edema volume in patients with subsequent hematoma contraction is larger, which is consistent with the hypothesis that acute edema represents successful hemostasis.

Abstract 61: Safety and Feasibility of Acute Dabigatran Therapy in Minor Ischemic Stroke Patients Without Atrial Fibrillation

Introduction: Transient Ischemic Attack (TIA) and Minor ischemic stroke (MIS) patients are at high risk for recurrent events. Older anticoagulants are associated with a reduction in recurrent events, but also an increase in hemorrhagic transformation (HT). Dabigatran etexilate (DE), a novel oral anticoagulant that is associated with reduced risk of intracranial bleeding in atrial fibrillation (AF) patients, may be an effective therapy in this population. DE is not indicated within 14 days of ischemic stroke, due to an absence of data. We tested the feasibility and safety of initiating DE therapy within 24 h of TIA/MIS.

Methods: We designed a 50 patient single arm open label treatment trial. The primary endpoint was symptomatic HT within 30 days of enrolment. All patients underwent MRI prior to treatment. TIA/MIS patients (NIHSS score ≤3) with a DWI lesion were prospectively treated with DE 150 mg BID (110 mg BID in patients ≥ 80 or if CrCl <40 ml/min). Treatment began within 24 h of onset and continued for 30 days. Patients with known atrial fibrillation (AF) were excluded. Patients were re-imaged at day 7 and 30, with clinical assessment to 90 days.

Results: Forty-three of 50 patients have been enrolled to date (March 2012-August 2013). The mean age was 66±12 years and median (IQR) NIHSS was 1 (2). Median baseline DWI volume was 0.89(1.9) ml. The median time from onset to initial DE dose was 18.5 (12.2) h. Therapy was completed in 41 patients and discontinued in two (withdrawal of consent (1) and dysphagia (1)). Two patients died within the 90 day study period, both after completion of DE therapy. No patients experienced systemic bleeding or symptomatic intracranial hemorrhage. One patient had asymptomatic HT (ECASS grade, HI1) on day 7, which resolved by day 30 despite continuing DE. No patients experienced recurrent clinical stroke. New asymptomatic DWI lesions developed in 7 (16%) patients by day 30.

Conclusion: These preliminary data suggest DE may be used safely in acute TIA/MIS patients and larger randomized trials are warranted. The low HT rate may make DE an ideal antithrombotic for use immediately after TIA/ischemic stroke.

Abstract 33: Cerebral Blood Flow in Leukoaraiosis Regions is Unaffected by Acute Lowering of Blood Pressure in Intracerebral Hemorrhage Patients

Introduction: Leukoariosis(LA) is associated with poor prognosis in intracerebral hemorrhage (ICH) patients. Patients with chronic small vessel ischemic changes may be more vulnerable to decreases in cerebral perfusion, in both LA and perihematoma(PH) regions. We tested the hypotheses that acute blood pressure reduction (BP) in ICH patients is associated with decreased cerebral blood flow (CBF) in areas of LA and the PH region.

Methods: In the ICH Acutely Decreasing Arterial Pressure Trial (ICH ADAPT), patients with ICH <24 hours duration were randomized to two systolic BP (SBP) target groups (<150 mmHg vs. <180 mmHg). Computed tomography (CT) perfusion imaging was performed 2 h post-randomization. LA tissue volume was planimetrically measured on the acute non-contrast CT, using Hounsfield Unit thresholds of 15-25. CBF, cerebral blood volume (CBV), and Tmax were measured in the LA regions.

Results: Seventy-one patients were included with a mean age of 69.3±11.5 years and median (IQR) baseline NIHSS score of 10(11). LA was present in 74.6% (53/71) and the median volume was 8.5(20.6) ml. LA was associated with older age (70.9± 11.2 vs. 64.8 ±11.6, p=0.05) and larger ICH volumes (19.52(29.78) vs. 9.52(16.02) ml, p=0.007). Mean CBF in LA regions (32.5±13.5) was similar to that in normal appearing white matter (35.6±12.1, p=0.3). Despite a significant drop in SBP between aggressive (36.25(40) mmHg) and conservative (18.5(29) mmHg, p=0.01) treatment groups, relative CBF (rCBF) in LA regions was unaffected (0.88±0.1 vs. 0.89±0.09, p=0.6). Similarly, aggressive BP treatment did not affect relative CBV (0.83±0.16 vs. 0.82± 0.15, p=0.8) or Tmax (7.3±3.2 s vs. 6.5 ±2.4 s, p=0.3). The rCBF in the PH regions in patients’ with/without LA was similar (0.88±0.09 vs. 0.86±0.1, p=0.5). There was a trend to worse functional outcome at 90 days, measured with the modified Rankin Scale in patients with LA (4(4) vs. 2(1), p=0.06).

Conclusion: LA is associated with larger baseline ICH volumes, but no differences in perihematoma CBF or the response to BP reduction. CBF in LA tissue is also unaffected by BP reduction. These data do not support a less aggressive approach to BP reduction in elderly patients with imaging evidence of chronic small vessel ischemia.

Insular ischemic stroke: clinical presentation and outcome

Background

The insula is a small but complex structure located in the depth of the sylvian fissure, covered by the frontal, parietal and temporal operculum. Ischemic strokes limited to the insula are rare and have not been well studied. Our objective is to better define the clinical presentation and outcome of insular ischemic strokes (IIS).

Methods

We reviewed the institutional prospective, consecutive stroke database from two centers to identify patients with IIS seen between 2008 and 2010. We also searched the Medline database using the keywords insula(r), infarction and stroke to identify previously published IIS cases confirmed by MRI. Minimal extension to an adjacent operculum or subinsular area was accepted. Clinicoradiological correlation was performed by distinguishing IIS involving the anterior (AIC) or posterior insular cortex (PIC). We collected clinical, demographic and radiological data. The outcome was determined using the modified Rankin Scale (mRS).

Results

We identified 7 patients from our institutions and 16 previously published cases of IIS. Infarcts were limited to the AIC (n = 4) or the PIC (n = 12) or affected both (n = 7). The five most frequent symptoms were somatosensory deficits (n = 10), aphasia (n = 10), dysarthria (n = 10), a vestibular-like syndrome (n = 8) and motor deficits (n = 6). A significant correlation was found between involvement of the PIC and somatosensory manifestations (p = 0.04). No other statistically significant associations were found. IIS presentation resembled a partial anterior circulation infarct (n = 9), a lacunar infarct (n = 2) or a posterior circulation infarct (n = 2). However, most cases presented findings that did not fit with these classical patterns (n = 10). At the 6 month follow up, mRS was 0 in 8/23 (35%) patients, 1–2 in 7/23 (30%) and unknown in 8/23 (35%).

Conclusions

IIS presentation is variable. Due to the confluence of functions in a restricted region, it results in multimodal deficits. It should be suspected when vestibular-like or motor but especially somatosensory, speech or language disturbances are combined in the same patient. The outcome of IIS is often favorable. Larger prospective studies are needed to better define the clinical presentation and outcome of IIS.

Systemic adverse events during 2005 phacoemulsifications under monitored anesthesia care: a prospective evaluation

BACKGROUND

The aim of the study was to evaluate the systemic adverse events triggering on-call anesthesiologist's intervention during 2005 phacoemulsification under topical anesthesia on a day-surgery monitored anesthesia care regimen.

METHODS

Adverse events triggering an anesthesiologist call by the attending nurse were registered. Comorbidities (7 categories), age, gender, body mass index, ASA status, length of surgery, time of the day of surgery and operated eye (first/second) were analyzed as potentially predictive factors. Odds Ratios are expressed as OR (95% CI).

RESULTS

The anesthesiologist was called in 433 (21.6%) cases: age (5-yr-OR 0.95 [0.91-0.99]), ASA status 3-4 (OR 1.37 [1.02-1.85]), positive neurological history (OR 1.60 [1.06-2.40]), positive psychiatric history (OR 2.56 [1.34-4.93]) and length of surgery (OR 1.03 [1.01-1.06]) were predictive of the anesthesiologist call. Arterial hypertension (10.3%) and agitation (9.5%) were the most frequent adverse events. Age (5-yr-OR 1.27 [1.16-1.38]) and ASA status 3-4 (OR 1.83 [1.30-2.56]) were predictive of arterial hypertension. Age (5-yr-OR 0.80 [0.76-0.85]), positive neurological history (OR 1.86 [1.10-3.14]) and positive psychiatric history (OR 4.48 [2.26-8.88]) were predictive of agitation. Interruption of surgery was never required.

CONCLUSION

One-day cataract surgery performed under topical anesthesia with monitored anesthesia care required anesthesiologist intervention in 21.6% of cases, mainly because of agitation or hypertension. Agitation occurred more often in younger patients with neurological or psychiatric comorbidities. Hypertension occurred more often in older patients with higher ASA scores.

Primary Angiitis of the Central Nervous System - Clinical Approaches, Challenges and Controversies

Primary angiitis of the central nervous system (PACNS) is a rare and life-threatening form of vasculitis confined to the CNS. A timely diagnosis is a real challenge because clinical manifestations of PACNS are diverse and nonspecific. Headaches, cerebrospinal fluid inflammation and abnormal brain magnetic resonance imaging are prevalent. When PACNS is suspected, a thorough investigation is mandatory to rule out several potential simulators and confirm the diagnosis. Treatment of PACNS is also a challenge involving competing forces, which include the threat of serious adverse effects of potent immunosuppressive agents and the risk of neurological deteriorations due to insufficient immunosuppressant therapy. Efforts are ongoing to delineate subtypes requiring different therapeutic approaches and having distinct prognoses. Despite recent progress, PACNS is still fatal in as much as one-sixth of cases. Long-term follow-up is mandatory in patients with PACNS.

Fusion as the result of sperm–somatic cell interaction

The research has been designed to investigate whether acrosome-reacted spermatozoa can fuse with somatic cells and to check whether this event may involve the molecular machinery implicated in the sperm–egg fusion. Boar spermatozoa were capacitatedin vitroand then treated with A23187 to induce acrosome reaction and activate their fusogenic potential. Reacted spermatozoa, loaded with the membrane-permeant fluorescent dye calcein AM, were incubated with plated granulosa cells or cells derived from stable cell lines: CRFK, VERO, and ESK4. The fusion between spermatozoa and somatic cells was revealed by the diffusion of the fluorescent dye from the sperm to the cell as membrane fusion and cytoplasmic continuity between the two cells were established. The involvement of integrin α6 and tetraspanin CD9 in the process of fusion was assessed by carrying out the experiment in the presence of antibodies against these molecules. Moreover, the incidence of fusion displayed by the different cell types used was analyzed in relation to their content in the above molecules assessed by western blot and immunostaining. The role of CD9 was additionally investigated by using CD9-negative cells. The data presented demonstrate that boar spermatozoa can fuse with different somatic cell types derived from different species and the process requires the combined presence of both integrin and tetraspanin molecules on the cell plasma membrane.

Spatio-temporal analysis of vascular endothelial growth factor expression and blood vessel remodelling in pig ovarian follicles during the periovulatory period

Vascular endothelial growth factor (VEGF) expression pattern and blood vessel remodelling were evaluated during the transition from the preovulatory follicle to the corpus luteum (CL). To this end, prepubertal gilts were treated with equine chorionic gonadotrophin (eCG) to collect preovulatory follicles (60 h after eCG) and with human chorionic gonadotrophin (hCG) to obtain periovulatory follicles 18 h and 36 h later. The VEGF mRNA content was analysed by in situ hybridization, while protein localization in follicular fluid (FF) and in granulosa and theca compartments was evaluated by ELISA, immunohistochemistry or western blot. Blood vessel architecture and vascular area (VA) were investigated using immunohistochemistry for von Willenbrand Factor, a specific endothelial marker. Vascular remodelling was finally tested using Ki-67 immunocytochemistry as a proliferation marker, or alpha-smooth muscle actin (alpha-SMA) as a specific mural cell marker. eCG-treated follicles showed high VEGF levels and two concentric blood vessel networks composed of proliferating endothelial cells without any association with mural components. hCG injection inhibited VEGF synthesis in the granulosa compartment and, as a consequence, the protein fell within the FF. In parallel, endothelial cell proliferation stopped and the VA decreased. Close to ovulation, VEGF production restarted in both follicular compartments and VEGF mRNA content significantly increased in the theca layer. Changes in follicular VEGF secretion were observed; the protein disappeared from FF and was observed in the extracellular matrix. An active angiogenesis characterized the follicle; endothelial cell proliferation was associated with a recruitment of alpha-SMA-positive mural cells. The data presented in this work showed that, in the phases preceding ovulation, a complete vascular remodelling occurs, characterized by both an evident neovascularization and the appearance of blood vessels presenting smooth musculature which could be involved in CL formation after ovulation.

Chronic cocaine-mediated changes in non-human primate nucleus accumbens gene expression

Chronic cocaine use elicits changes in the pattern of gene expression within reinforcement-related, dopaminergic regions. cDNA hybridization arrays were used to illuminate cocaine-regulated genes in the nucleus accumbens (NAcc) of non-human primates (Macaca fascicularis; cynomolgus macaque), treated daily with escalating doses of cocaine over one year. Changes seen in mRNA levels by hybridization array analysis were confirmed at the level of protein (via specific immunoblots). Significantly up-regulated genes included: protein kinase A alpha catalytic subunit (PKA(calpha)); cell adhesion tyrosine kinase beta (PYK2); mitogen activated protein kinase kinase 1 (MEK1); and beta-catenin. While some of these changes exist in previously described cocaine-responsive models, others are novel to any model of cocaine use. All of these adaptive responses coexist within a signaling scheme that could account for known inductions of genes(e.g. fos and jun proteins, and cyclic AMP response element binding protein) previously shown to be relevant to cocaine's behavioral actions. The complete data set from this experiment has been posted to the newly created Drug and Alcohol Abuse Array Data Consortium (http://www.arraydata.org) for mining by the general research community.

A cocaine analog, 2beta-propanoyl-3beta-(4-tolyl)-tropane (PTT), reduces tyrosine hydroxylase in the mesolimbic dopamine pathway

Tyrosine hydroxylase (TH) is the rate-limiting enzyme in catecholamine biosynthesis. Previously published results have established that chronic cocaine administration (30-45 mg/kg per day, 10-14 days) resulted in an upregulation of TH gene expression in dopaminergic pathways of rats. The present studies tested the effects of a tropane analog, PTT (2beta-propanoyl-3beta-(4-tolyl)-tropane), on TH expression. This drug has similar actions to cocaine, but possesses markedly different pharmacokinetics (20 times more potent at binding the dopamine transporter, markedly increased metabolic stability, and 10-20 times more potent in behavioral measures). Moreover, PTT demonstrates an increased selectivity for the dopamine (DA) and norepinephrine (NE) transporters compared with cocaine. In direct contrast to the previously reported effects of cocaine, 10 days of PTT administration (3.0 mg/kg per day, i.p.) produced a uniform downregulation of TH protein and activity gene expression. TH activity and immunoreactive protein where decreased by 54 and 69%, respectively in the nucleus accumbens. Within the ventral tegmental area, TH activity and protein were decreased by 33 and 19%, respectively. The underlying mechanisms for these fundamental differences are unclear, but likely reflect varying and selective affinities and lengths of occupancy at biogenic amine transporters.

Nerve growth factor production in sheep antral follicles

Despite their continuous turnover, sheep antral follicles are always regularly innervated. The local production of neurotrophins is probably involved in the control of ovarian innervation. In this context the present investigation was designed to evaluate the ability of sheep antral follicles to produce neurotrophic factors. In the first part of the paper neurotrophic activity was measured in follicular fluid of sheep antral follicles of different size. Using an in vitro model the effect of gonadotrophins on neurotrophin production was then evaluated. The levels of neurotrophic activity in conditioned medium or follicular fluid and the kind of neurotrophin produced were determined by using the chicken embryo dorsal root ganglia test combined with an immunoneutralization step. Follicular fluid from medium-large follicles (>4 mm) contains high levels of NGF (240-250 ng/ml), whereas the factor is nearly undetectable in small follicles (<3 mm) and in early atretic follicles. Experiments in vitro based on the culture of follicle shells for 12 hr confirmed that medium-large follicles can produce NGF. The production is strictly dependent on gonadotrophin stimulation. When gonadotrophins were not added or were added separately, no detectable levels of neurotrophic activity accumulated in medium. By contrast, in the presence of both LH and FSH the production of NGF became apparent showing a clear dose-response behavior. In addition, this production increased progressively with increasing follicle size from 4 to >5 mm up to values of about 60 ng/follicle, whereas follicles with a diameter of less than 3 mm were insensitive to gonadotrophins stimulation and did not produce significant amount of NGF. The data presented demonstrate that sheep follicles produce relevant amounts of NGF as long as the correct hormonal milieu is provided. Under these conditions the production of the NGF increases with increasing follicle size. This may be responsible for the rapid innervation of the wall of growing follicles and/or take part in other non-neural processes that are generally attributed to gonadotrophin stimulation.

Peribulbar anesthesia with either 0.75% ropivacaine or a 2% lidocaine and 0.5% bupivacaine mixture for vitreoretinal surgery: a double-blinded study

No study has evaluated the efficacy of ropivacaine in peribulbar block for ophthalmic surgery. The purpose of this prospective, randomized, double-blinded study was to compare ropivacaine and a lidocaine-bupivacaine mixture in peribulbar anesthesia. Sixty ASA physical status I or II patients scheduled for elective vitreoretinal surgery were randomized to receive a peribulbar block with 8 mL of either 0.75% ropivacaine (ropivacaine group, n = 30) or a 1:1 mixture of 2% plain lidocaine and 0.5% plain bupivacaine (lido-bupivacaine group, n = 30). Time required for onset of surgical anesthesia, quality of postoperative analgesia, incidence of side effects, and analgesic consumption were recorded. Surgical block was achieved after 8 +/- 5 min in the lido-bupivacaine group and after 10 +/- 5 min in the ropivacaine group (P = 0.23). A 3-mL supplemental injection 15 min after block placement was required in 6 patients in the lido-bupivacaine group (20%) and in 10 patients in the ropivacaine group (33%) due to inadequate motor block (P = 0.38). On Postoperative Day 1, 26 patients in the ropivacaine group (87%) reported no pain at the verbal rating score, compared with 18 patients in the lido-bupivacaine group (60%) (P = 0.005). We conclude that 0.75% ropivacaine may be a suitable choice when performing peribulbar anesthesia for vitreoretinal surgery.

IMPLICATIONS

Quick onset of block with prolonged postoperative analgesia is an important goal in regional anesthesia for ophthalmic surgery. Evaluating clinical properties of 0.75% ropivacaine and a 1:1 mixture of 2% lidocaine and 0.5% bupivacaine for peribulbar anesthesia, we demonstrated that ropivacaine has an onset similar to that of the lidocaine-bupivacaine mixture and provides a better quality of postoperative analgesia.

Lightwand intubation does not reduce the increase in intraocular pressure associated with tracheal intubation

OBJECTIVE

To evaluate the changes in hemodynamic variables and intraocular pressure (IOP) after tracheal intubation using either lightwand or direct-vision laryngoscopy techniques.

DESIGN

Prospective, randomized study.

SETTING

Inpatient anesthesia at a University Anesthesia Department.

PATIENTS

50 normotensive, ASA physical status I and II patients, without ocular or cardiovascular diseases, and with a Mallampati score no greater than 2.

INTERVENTIONS

After intravenous (i.v.) midazolam premedication (0.05 mg.kg-1), general anesthesia was induced with fentanyl (1 microgram.g-1) and thiopental sodium (5 mg.g-1) followed by vecuronium bromide (0.1 mg.g-1), then patients were randomly allocated to receive either the lightwand (Trachlight, n = 25) or direct-vision laryngoscopy (Laryngoscopy, n = 25) intubating techniques. General anesthesia was maintained with 1% isoflurane and 60% nitrous oxide in oxygen mixture for 5 minutes.

MEASUREMENTS AND MAIN RESULTS

Baseline hemodynamic variables were recorded 10 minutes after i.v. premedication, and then every minute after tracheal intubation. Intraocular pressure measurements were performed by means of a computerized indentation tonometer after general anesthesia induction and then 1 and 5 minutes after tracheal intubation. In both groups, mean arterial blood pressure and heart rate increased from baseline, without differences between the two groups. One minute after intubation, IOP increased in both groups: the mean percentage increase was 32% in the Laryngoscopy group and 16% in the Trachlight group. However, this difference was not statistically significant. Five minutes after intubation, IOP decreased to baseline values in both groups.

CONCLUSION

We conclude that in healthy patients without ocular disease, using a lightwand intubating technique does not reduce the hemodynamic responses and increase in IOP associated with tracheal intubation as compared with conventional direct-vision laryngoscopy.

Biochemical and biological effects of KN-93, an inhibitor of calmodulin-dependent protein kinase II, on the initial events of mouse egg activation induced by ethanol

Calmodulin-dependent protein kinase II (CaMKII) is transiently activated in mouse eggs by the increase in calcium that occurs upon activation with ethanol. This study investigated the biological and biochemical effects of KN-93, a reported selective inhibitor of CaMKII, to explore the potential role of this kinase in the initial events of egg activation. Mouse eggs were incubated for 30 min in the presence of different concentrations of KN-93 and induced to activate by 7% ethanol. KN-93 elicited a dose-dependent inhibition of polar body emission that resulted from the failure of the eggs to undergo meiosis resumption and inactivation of maturation-promoting factor (MPF). Furthermore, 15 mumol KN-93 l-1 produced a marked reduction in ethanol-induced loss of cortical granules. In vivo biochemical analysis revealed that 15 mumol KN-93 l-1 was responsible for significant inhibition of ethanol-stimulated CaMKII. The activity of the enzyme remained at a resting value, in spite of the presence of a calcium signal similar to that measured in control activated eggs. The inhibitory effects of KN-93 on the parameters tested in this study could not be mimicked by the inactive analogue KN-92. These results show that in mouse eggs, when ethanol-induced CaMKII activation was prevented, cortical granule exocytosis and meiosis resumption were inhibited. This suggests that CaMKII acts as a switch in the transduction of the calcium signal triggering mammalian egg activation.