Mesoscale oceanographic meanders influence protist community function and structure in the southern Indian Ocean.

The interface between the nutrient-rich Southern Ocean and oligotrophic Indian Ocean creates unique environmental conditions that can strongly influence biological processes. We investigated protist communities across a mesoscale meander of the Subtropical Front within the Southern Indian Ocean. 18S V9 rDNA metabarcoding suggests a diverse protist community in which the dinoflagellates and parasitic Syndiniales were abundant. Diversity was highest in frontal waters of the mesoscale meander, with differences in community structure inside and outside the meander. While the overall community was dominated by mixotrophic taxa, the frontal boundary of the meander had increased abundances of heterotrophic taxa, with potential implications for net atmospheric CO2 drawdown. Pulse amplitude modulated (PAM) fluorimetry revealed significant differences in the photophysiology of phytoplankton communities inside and outside the meander. By using single-cell PAM microscopy, we identified physiological differences between dinoflagellate and coccolithophore taxa, which may have contributed to changes in photophysiology observed at community level. Overall, our results demonstrate that frontal areas have a strong impact on the composition of protist communities in the Southern Ocean with important implications for understanding biological processes in this region.

A systematic review of the Woven EndoBridge device-do findings in pre-clinical animal models compare to clinical results?

BACKGROUND: The Woven Endobridge (WEB) is designed to treat intracranial wide-neck bifurcation aneurysms, preventing subarachnoid hemorrhage. The translational value of animal models used for WEB device testing is unknown. With this systematic review, we aim to identify the existing animal models used in testing the WEB device and compare the efficacy and safety outcomes to those of prospective clinical studies. METHODS: This study was funded by ZonMw: project number 114024133. A comprehensive search was performed in PubMed and in EMBASE via the Ovid interface. The following exclusion criteria were used: 1) not an original full-length research paper, 2) not an in vivo animal study or a human study, 3) no WEB implantation, 4) if in humans: not a prospective study. The SYRCLE risk of bias tool (animal studies) and the Newcastle-Ottawa quality assessment scale for cohort studies (clinical studies) were used to assess risks of bias. A narrative synthesis was performed. RESULTS: Six animal studies and 17 clinical studies met the inclusion criteria. The rabbit elastase aneurysm model was the only animal model used to assess WEB device performance. Safety outcomes were never reported in animal studies. Efficacy outcomes were more heterogeneous in animal studies than in clinical studies, which could be due to limited external validity of the animal models in terms of aneurysm induction and dimensions. Both animal and clinical studies were predominantly single-arm studies, and were at unclear risk of several types of bias. CONCLUSIONS: The rabbit elastase aneurysm model was the only pre-clinical animal model used to assess WEB device performance. Safety outcomes were not evaluated in animal studies and could therefore not be compared to clinical outcomes. Efficacy outcomes were more heterogeneous in animal studies than in clinical studies. Future research should focus on improving methodology and reporting in order to draw accurate conclusions on the performance of the WEB device.

Animal Models for Studying Protein-Bound Uremic Toxin Removal-A Systematic Review.

Protein-bound uremic toxins (PBUTs) are associated with the progression of chronic kidney disease (CKD) and its associated morbidity and mortality. The conventional dialysis techniques are unable to efficiently remove PBUTs due to their plasma protein binding. Therefore, novel approaches are being developed, but these require validation in animals before clinical trials can begin. We conducted a systematic review to document PBUT concentrations in various models and species. The search strategy returned 1163 results for which abstracts were screened, resulting in 65 full-text papers for data extraction (rats (n = 41), mice (n = 17), dogs (n = 3), cats (n = 4), goats (n = 1), and pigs (n = 1)). We performed descriptive and comparative analyses on indoxyl sulfate (IS) concentrations in rats and mice. The data on large animals and on other PBUTs were too heterogeneous for pooled analysis. Most rodent studies reported mean uremic concentrations of plasma IS close to or within the range of those during kidney failure in humans, with the highest in tubular injury models in rats. Compared to nephron loss models in rats, a greater rise in plasma IS compared to creatinine was found in tubular injury models, suggesting tubular secretion was more affected than glomerular filtration. In summary, tubular injury rat models may be most relevant for the in vivo validation of novel PBUT-lowering strategies for kidney failure in humans.

Evidence on continuous flow peritoneal dialysis: A review.

Clinical application of continuous flow peritoneal dialysis (CFPD) has been explored since the 1960s, but despite anticipated clinical benefits, CFPD has failed to gain a foothold in clinical practice, among others due to the typical use of two catheters (or a dual-lumen catheter) and large dialysate volumes required per treatment. Novel systems applying CFPD via the existing single-lumen catheter using rapid dialysate cycling may solve one of these hurdles. Novel on-demand peritoneal dialysate generation systems and sorbent-based peritoneal dialysate regeneration systems may considerably reduce the storage space for peritoneal dialysate and/or the required dialysate volume. This review provides an overview of current evidence on CFPD in vivo. The available (pre)clinical evidence on CFPD is limited to case reports/series with inherently nonuniform study procedures, or studies with a small sample size, short follow-up, and no hard endpoints. Small solute clearance appears to be higher in CFPD compared to conventional PD, in particular at dialysate flows ≥100 mL/min using two single-lumen catheters or a double-lumen catheter. Results of CFPD using rapid cycling via a single-lumen catheter are too preliminary to draw any conclusions. Continuous addition of glucose to dialysate with CFPD appears to be effective in reducing the maximum intraperitoneal glucose concentration while increasing ultrafiltration efficiency (mL/g absorbed glucose). Patient tolerance may be an issue since abdominal discomfort and sterile peritonitis were reported with continuous circulation of the peritoneal dialysate. Thus, well-designed clinical trials of longer duration and larger sample size, in particular applying CFPD via the existing catheter, are urgently required.

Time trends in the risk of delayed cerebral ischemia after subarachnoid hemorrhage: a meta-analysis of randomized controlled trials.

OBJECTIVE: Delayed cerebral ischemia (DCI) contributes to morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Continuous improvement in the management of these patients, such as neurocritical care and aneurysm repair, may decrease the prevalence of DCI. In this study, the authors aimed to investigate potential time trends in the prevalence of DCI in clinical studies of DCI within the last 20 years. METHODS: PubMed, Embase, and the Cochrane library were searched from 2000 to 2020. Randomized controlled trials that reported clinical (and radiological) DCI in patients with aSAH who were randomized to a control group receiving standard care were included. DCI prevalence was estimated by means of random-effects meta-analysis, and subgroup analyses were performed for the DCI sum score, Fisher grade, clinical grade on admission, and aneurysm treatment method. Time trends were evaluated by meta-regression. RESULTS: The search strategy yielded 5931 records, of which 58 randomized controlled trials were included. A total of 4424 patients in the control arm were included. The overall prevalence of DCI was 0.29 (95% CI 0.26-0.32). The event rate for prevalence of DCI among the high-quality studies was 0.30 (95% CI 0.25-0.34) and did not decrease over time (0.25% decline per year; 95% CI -2.49% to 1.99%, p = 0.819). DCI prevalence was higher in studies that included only higher clinical or Fisher grades, and in studies that included only clipping as the treatment modality. CONCLUSIONS: Overall DCI prevalence in patients with aSAH was 0.29 (95% CI 0.26-0.32) and did not decrease over time in the control groups of the included randomized controlled trials.

(No) escape from reality? Cigarette craving in virtual smoking environments.

Cue-Exposure Therapy (CET) is considered an effective strategy to combat cigarette cravings and smoking relapses, but evidence is mixed. In this lab-based experimental study, we manipulated levels of realism for smoking scenarios in Virtual Environments (VE) and randomly exposed smokers and recent-quitters to one of two versions (low versus high realism) of these scenarios. Prior and after scenario exposure, valid measures of cigarette craving were obtained. Prior to exposure, we assessed nicotine dependence and smoking status (current smokers versus recent-quitter). Within-subject repeated measures analysis of covariance showed that there was an interaction of experimental condition with smoking status on cigarette craving. Amongst recent-quitters, high realistic scenarios produced stronger increases in craving than low realistic scenarios, but this effect was reversed in current smokers. It is concluded that VE technologies are a potentially relevant tool for smoking CET that warrant further exploration.

Endovascular aneurysm closure during out of office hours is not related to complications or outcome.

PURPOSE: A possible disadvantage of endovascular occlusion outside work hours is that complex procedures might expose patients to additional risk when performed in a suboptimal setting. In this prospective cohort study, we evaluated whether treatment during out of office hours is a risk factor for per-procedural complications and clinical outcome. METHODS: We included 471 endovascular-treated, consecutive aneurysmal subarachnoid hemorrhage patients (56.6 ± 13.1, 69% female), from two prospective observational databases which were retrospectively analyzed. Primary outcome was the occurrence of per-procedural complications. Secondary outcomes were good clinical outcome (modified ranking scale ≤ 2) and death at 6-month follow-up. We determined odds ratios (OR) with 95% confidence intervals (CI) by ordered polytomous logistic regression analysis and adjusted odds ratios (aOR) for age, World Federation of Neurosurgical Societies grade, and time to treatment. RESULTS: Most patients were treated during office hours (363/471; 77.1%). Treatment during out of office hours did not result in an increased risk of per-procedural complications (OR 0.85 (95% CI 0.53-1.37; p = 0.51). Patients treated during out of office hours displayed similar odds of good clinical outcome and death after 6 months (OR 1.14, 95% CI 0.68-1.97 and 1.16 95% CI 0.56-2.29, respectively) compared to patients treated during office hours. CONCLUSION: In our study, endovascular coil embolization during out of office hours did not expose patients to an increased risk of procedural complications or affect functional outcome after 6 months.

Presence of inflammatory proteins S100A8 and S100A9 in a giant intracranial aneurysm after flow diverter treatment.

We demonstrate the presence of S100A8 and S100A9 proteins in the wall and thrombosed lumen of an enlarged intracranial aneurysm after flow diverter treatment. These proteins have shown to play an important role in vascular inflammation and may serve as a biomarker and potential therapeutic target for intracranial aneurysms.

A randomized trial of intraarterial treatment for acute ischemic stroke.

BACKGROUND: In patients with acute ischemic stroke caused by a proximal intracranial arterial occlusion, intraarterial treatment is highly effective for emergency revascularization. However, proof of a beneficial effect on functional outcome is lacking. METHODS: We randomly assigned eligible patients to either intraarterial treatment plus usual care or usual care alone. Eligible patients had a proximal arterial occlusion in the anterior cerebral circulation that was confirmed on vessel imaging and that could be treated intraarterially within 6 hours after symptom onset. The primary outcome was the modified Rankin scale score at 90 days; this categorical scale measures functional outcome, with scores ranging from 0 (no symptoms) to 6 (death). The treatment effect was estimated with ordinal logistic regression as a common odds ratio, adjusted for prespecified prognostic factors. The adjusted common odds ratio measured the likelihood that intraarterial treatment would lead to lower modified Rankin scores, as compared with usual care alone (shift analysis). RESULTS: We enrolled 500 patients at 16 medical centers in The Netherlands (233 assigned to intraarterial treatment and 267 to usual care alone). The mean age was 65 years (range, 23 to 96), and 445 patients (89.0%) were treated with intravenous alteplase before randomization. Retrievable stents were used in 190 of the 233 patients (81.5%) assigned to intraarterial treatment. The adjusted common odds ratio was 1.67 (95% confidence interval [CI], 1.21 to 2.30). There was an absolute difference of 13.5 percentage points (95% CI, 5.9 to 21.2) in the rate of functional independence (modified Rankin score, 0 to 2) in favor of the intervention (32.6% vs. 19.1%). There were no significant differences in mortality or the occurrence of symptomatic intracerebral hemorrhage. CONCLUSIONS: In patients with acute ischemic stroke caused by a proximal intracranial occlusion of the anterior circulation, intraarterial treatment administered within 6 hours after stroke onset was effective and safe. (Funded by the Dutch Heart Foundation and others; MR CLEAN Netherlands Trial Registry number, NTR1804, and Current Controlled Trials number, ISRCTN10888758.).

Operating room waste: disposable supply utilization in neurointerventional procedures.

BACKGROUND: Operating rooms account for 70% of hospital waste, increasing healthcare costs and creating environmental hazards. Endovascular treatment of cerebrovascular pathologies has become prominent, and associated products highly impact the total cost of care. We investigated the costs of endovascular surgical waste at our institution. METHODS: Data from 53 consecutive endovascular procedures at the Radboud UMC Nijmegen from May to December 2016 were collected. "Unused disposable supply" was defined as one-time use items opened but not used during the procedure. Two observers cataloged the unused disposable supply for each case. The cost of each item was determined from the center supply catalog, and these costs were summed to determine the total cost of unused supply per case. RESULTS: Thirteen diagnostic cerebral digital subtraction angiographies (DSA) (24.5%) and 40 endovascular procedures (75.5%) were analyzed. Total interventional waste was 27,299.53 € (mean 515.09 € per procedure). While total costs of unused disposable supply were almost irrelevant for DSAs, they were consistent for interventional procedures (mean 676.49 € per case). Aneurysm standard coiling had the highest impact on total interventional waste (mean 1061.55 €). Disposable interventional products had a very high impact on the surgical waste costs in the series of the neurointerventional procedures (95% of total waste). CONCLUSIONS: This study shows the impact of neurointerventional waste on the total care costs for cerebrovascular patients. This might reflect the tendency to anticipate needs and emergencies in neurointervention. Responsible use of disposable material can be achieved by educating operators and nurses and creating operator preference cards.

Treatment of patients with ruptured aneurysm by neurosurgeons that perform both open surgical and endovascular techniques is safe and effective: results of a single centre in Europe.

In Europe only few neurosurgeons are trained in both open surgical clipping as well as in endovascular techniques for treatment of intracranial aneurysms. To investigate the safety and efficacy of performing both techniques we, two dual trained neurosurgeons, analyzed our results in repairing ruptured intracranial aneurysms. Prospectively collected data from 356 patients that underwent open surgical or endovascular repair of a ruptured intracranial aneurysm at the Neurosurgical Centre Nijmegen from 2006 to 2012 by two dual trained neurosurgeons were retrospectively analyzed. Complication rates, occlusion rates, and retreatment rates were obtained. Combined procedural persistent neurological morbidity and mortality after endovascular treatment and open surgical clipping were 2.1 % and 1.4 %, respectively. Overall procedure-related clinical complication rate for endovascular treatment was 5.9 % in 285 procedures for 295 aneurysms. Overall procedure-related clinical complication rate for open treatment was 9.9 % in 71 procedures for 72 aneurysms. Follow-up was available for 255 out of 295 coiled aneurysms, 48 aneurysms recurred and 34 needed retreatment. For clipping 54 out of 72 treated aneurysms had follow-up; four aneurysms were incompletely clipped. One aneurysm was retreated. Treatment of ruptured intracranial aneurysms by neurosurgeons that perform both open surgical clipping as well as endovascular techniques is safe and effective. Developing training programs in Europe for hybrid neurosurgeons that can provide comprehensive patient care should be considered.

The value of the Charlson Co-morbidity Index in aneurysmal subarachnoid haemorrhage.

BACKGROUND: Several studies have included different co-morbid conditions in prediction models for stroke patients. For subarachnoid haemorrhage (SAH), it is not known whether the Charlson Co-morbidity Index (CCI) is associated with outcome. We evaluated if this index was associated with outcome in patients with ruptured intracerebral aneurysms. METHODS: The data of all consecutive aneurysmal SAH (aSAH) patients treated at the Radboudumc, Nijmegen, The Netherlands and entered in the database were retrospectively analysed. Clinical condition at admission was recorded using the WFNS (World Federation of Neurological Surgeons Grading System) grade was collected, as were the age and treatment modality. The burden of co-morbidity was retrospectively registered using the CCI. Outcome was dichotomised on the modified Rankin Scale (mRS; 0-2, favourable outcome; 3-6, unfavourable outcome). A binary logistic regression analysis was performed. RESULTS: Between 6th May 2008 and 31st July 2013, 457 patients were admitted because of non-traumatic SAH (aSAH). Seventy-seven (16.8 %) patients had no aneurysm. Of the 380 patients with aSAH, information on co-morbid conditions was available for 371 patients. Thirty-six of those 371 had no treatment because of: bad clinical condition in 34 (9.2 %), a non-treatable dissecting aneurysm in 1 (0.3 %) and the explicit wishes of another. Co-morbidity was present in 113 (31.5 %) patients. Binary logistic regression analysis revealed no added value of using the CCI in predicting the outcome (p = 0.91). CONCLUSIONS: This study reports that the CCI is not associated with the outcome classified on the mRS at 6 months in patients after aSAH. The CCI has no added value in case-mix correction.

CASCADE: Dataset of extant coccolithophore size, carbon content and global distribution.

Coccolithophores are marine calcifying phytoplankton important to the carbon cycle and a model organism for studying diversity. Here, we present CASCADE (Coccolithophore Abundance, Size, Carbon And Distribution Estimates), a new global dataset for 139 extant coccolithophore taxonomic units. CASCADE includes a trait database (size and cellular organic and inorganic carbon contents) and taxonomic-unit-specific global spatiotemporal distributions (Latitude/Longitude/Depth/Month/Year) of coccolithophore abundance and organic and inorganic carbon stocks. CASCADE covers all ocean basins over the upper 275 meters, spans the years 1964-2019 and includes 33,119 gridded taxonomic-unit-specific abundance observations. Within CASCADE, we characterise the underlying uncertainties due to measurement errors by propagating error estimates between the different studies. This error propagation pipeline is statistically robust and could be applied to other plankton groups. CASCADE can contribute to (observational or modelling) studies that focus on coccolithophore distribution and diversity and the impacts of anthropogenic pressures on historical populations. Additionally, our new taxonomic-unit-specific cellular carbon content estimates provide essential conversions to quantify the role of coccolithophores on ecosystem functioning and global biogeochemistry.

Cellular morphological trait dataset for extant coccolithophores from the Atlantic Ocean.

Calcification and biomass production by planktonic marine organisms influences the global carbon cycle and fuels marine ecosystems. The major calcifying plankton group coccolithophores are highly diverse, comprising ca. 250-300 extant species. However, coccolithophore size (a key functional trait) and degree of calcification are poorly quantified, as most of our understanding of this group comes from a small number of species. We generated a novel reference dataset of coccolithophore morphological traits, including cell-specific data for coccosphere and cell size, coccolith size, number of coccoliths per cell, and cellular calcite content. This dataset includes observations from 1074 individual cells and represents 61 species from 25 genera spanning equatorial to temperate coccolithophore populations that were sampled during the Atlantic Meridional Transect (AMT) 14 cruise in 2004. This unique dataset can be used to explore relationships between morphological traits (cell size and cell calcite) and environmental conditions, investigate species-specific and community contributions to pelagic carbonate production, export and plankton biomass, and inform and validate coccolithophore representation in marine ecosystem and biogeochemical models.

New generation of Flow Diverter (surpass) for unruptured intracranial aneurysms: a prospective single-center study in 37 patients.

BACKGROUND AND PURPOSE: In patients harboring intracranial aneurysms, the major goal in treatment is to prevent bleeding. A new generation of an endoluminal device (Surpass Flow Diverter [Surpass]) was developed to reconstruct parent artery and occlude the aneurysm. We present our clinical and angiographic single-center experience. METHODS: Patients with a wide range of complex unruptured aneurysms were treated with the Surpass placed in the parent artery and bridging the aneurysm. Clinical and angiographic follow-up were performed at 6 months. Data were prospectively collected. RESULTS: Thirty seven patients (mean age, 56 years; range, 32-79), harboring 49 unruptured aneurysms were treated at our center. All except 1 patient were treated with a single device. Successful delivery of the device was achieved in all patients. All 35 nonbifurcation aneurysm necks were covered completely, whereas 14 bifurcation aneurysms were only partially covered. There was no major periprocedural morbidity or mortality. During follow-up, 4 patients (10.4%) experienced transient neurological deficit. One patient (3%) developed a minor stroke at 4-month follow-up with persistent neurological deficit. Twelve patients had neurological symptoms related to their aneurysm and 7 showed improvement of these symptoms during follow-up. At 6-month follow-up, 29 of 31 aneurysms studied that had complete neck coverage showed a complete occlusion (94%) including 1 case with a 95% to 100% occlusion, whereas 5 of the 10 bifurcation aneurysms were occluded. CONCLUSIONS: Our study shows high safety and efficacy profile of a new generation endoluminal device in treatment of complex intracranial aneurysms. Long-term studies of treated bifurcation aneurysms are needed.

European Stroke Organisation (ESO) - European Society for Minimally Invasive Neurological Therapy (ESMINT) Guidelines on Mechanical Thrombectomy in Acute Ischemic Stroke.

BACKGROUND: Mechanical thrombectomy (MT) has become the cornerstone of acute ischemic stroke management in patients with large vessel occlusion (LVO). OBJECTIVE: To assist physicians in their clinical decisions with regard toMT. METHODS: These guidelines were developed based on the standard operating procedure of the European Stroke Organisation and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. An interdisciplinary working group identified 15 relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert opinion was provided if not enough evidence was available to provide recommendations based on the GRADE approach. RESULTS: We found high-quality evidence to recommend MT plus best medical management (BMM, including intravenous thrombolysis whenever indicated) to improve functional outcome in patients with LVO-related acute ischemic stroke within 6 hours after symptom onset. We found moderate quality of evidence to recommend MT plus BMM in the 6-24h time window in patients meeting the eligibility criteria of published randomized trials. These guidelinesdetails aspects of prehospital management, patient selection based on clinical and imaging characteristics, and treatment modalities. CONCLUSIONS: MT is the standard of care in patients with LVO-related acute stroke. Appropriate patient selection and timely reperfusion are crucial. Further randomized trials are needed to inform clinical decision-making with regard tothe mothership and drip-and-ship approaches, anesthaesia modalities during MT, and to determine whether MT is beneficial in patients with low stroke severity or large infarct volume.

Portable, wearable and implantable artificial kidney systems: needs, opportunities and challenges.

Haemodialysis is life sustaining but expensive, provides limited removal of uraemic solutes, is associated with poor patient quality of life and has a large carbon footprint. Innovative dialysis technologies such as portable, wearable and implantable artificial kidney systems are being developed with the aim of addressing these issues and improving patient care. An important challenge for these technologies is the need for continuous regeneration of a small volume of dialysate. Dialysate recycling systems based on sorbents have great potential for such regeneration. Novel dialysis membranes composed of polymeric or inorganic materials are being developed to improve the removal of a broad range of uraemic toxins, with low levels of membrane fouling compared with currently available synthetic membranes. To achieve more complete therapy and provide important biological functions, these novel membranes could be combined with bioartificial kidneys, which consist of artificial membranes combined with kidney cells. Implementation of these systems will require robust cell sourcing; cell culture facilities annexed to dialysis centres; large-scale, low-cost production; and quality control measures. These challenges are not trivial, and global initiatives involving all relevant stakeholders, including academics, industrialists, medical professionals and patients with kidney disease, are required to achieve important technological breakthroughs.