Exploring the relation between turbulent velocity and density fluctuations in the stratified intracluster medium

Context. The dynamics of the intracluster medium (ICM) is affected by turbulence driven by several processes, such as mergers, accretion and feedback from active galactic nuclei. Aims. X-ray surface brightness fluctuations have been used to constrain turbulence in galaxy clusters. Here, we use simulations to further investigate the relation between gas density and turbulent velocity fluctuations, with a focus on the effect of the stratification of the ICM. Methods. In this work, we studied the turbulence driven by hierarchical accretion by analysing a sample of galaxy clusters simulated with the cosmological code ENZO. We used a fixed scale filtering approach to disentangle laminar from turbulent flows. Results. In dynamically perturbed galaxy clusters, we found a relation between the root mean square of density and velocity fluctuations, albeit with a different slope than previously reported. The Richardson number is a parameter that represents the ratio between turbulence and buoyancy, and we found that this variable has a strong dependence on the filtering scale. However, we could not detect any strong relation between the Richardson number and the logarithmic density fluctuations, in contrast to results by recent and more idealised simulations. In particular, we find a strong effect from radial accretion, which appears to be the main driver for the gas fluctuations. The ubiquitous radial bias in the dynamics of the ICM suggests that homogeneity and isotropy are not always valid assumptions, even if the turbulent spectra follow Kolmogorov's scaling. Finally, we find that the slope of the velocity and density spectra are independent of cluster-centric radii

Hepatitis C virus production requires apolipoprotein A-I and affects its association with nascent low-density lipoproteins

Background/aims The life cycle of hepatitis C virus (HCV) is intimately linked to the lipid metabolism of the host. In particular, HCV exploits the metabolic machinery of the lipoproteins in several steps of its life cycle such as circulation in the bloodstream, cell attachment and entry, assembly and release of viral particles. However, the details of how HCV interacts with and influences the metabolism of the host lipoproteins are not well understood. A study was undertaken to investigate whether HCV directly affects the protein composition of host circulating lipoproteins. Methods A proteomic analysis of circulating very low-, low- and high-density lipoproteins (VLDL, LDL and HDL), isolated from either in-treatment naive HCV-infected patients or healthy donors (HD), was performed using two-dimensional gel electrophoresis and tandem mass spectrometry (MALDI-TOF/TOF). The results obtained were further investigated using in vitro models of HCV infection and replication. Results A decreased level of apolipoprotein A-I (apoA-I) was found in the LDL fractions of HCV-infected patients. This result was confirmed by western blot and ELISA analysis. HCV cellular models (JFH1 HCV cell culture system (HCVcc) and HCV subgenomic replicons) showed that the decreased apoA-I/LDL association originates from hepatic biogenesis rather than lipoprotein catabolism occurring in the circulation, and is not due to a downregulation of the apoA-I protein concentration. The sole non-structural viral proteins were sufficient to impair the apoA-I/LDL association. Functional evidence was obtained for involvement of apoA-I in the viral life cycle such as RNA replication and virion production. The specific siRNA-mediated downregulation of apoA-I led to a reduction in both HCV RNA and viral particle levels in culture. Conclusions This study shows that HCV induces lipoprotein structural modification and that its replication and production are linked to the host lipoprotein metabolism, suggesting apoA-I as a new possible target for antiviral therapy

Sex Influence on Fenestrated and Branched Endovascular Aortic Aneurysm Repair: Outcomes From a National Multicenter Registry

Introduction: Women are generally underrepresented in trials focusing on aortic aneurysm. Nevertheless, sex-related differences have recently emerged from several studies and registries. The aim of this research was to assess whether sex-related anatomical disparities existed in fenestrated and branched aortic repair candidates and whether these discrepancies could influence endovascular repair outcomes. Methods: Data from all consecutive patients treated during the 2008–2019 period within the Italian Multicenter fenestrated or branched endovascular aortic repair (F/BEVAR) Registry were included in the present study. Propensity matching was performed using a logistic regression model adjusted for demographic data and comorbidities to obtain comparable male and female samples. The selection model led to a final study population of 176 patients (88 women and 88 men) among the total initial cohort of 596. Study endpoints were technical and clinical success, overall survival, aneurysm-related death, and reintervention rates evaluated at 30 days and during follow-up. Results: Twenty-eight patients (15.9%) received urgent/emergent repair. In most of the cases (71.6%), women received treatment for extensive thoracoabdominal pathology (Crawford type I, II, or III aneurysm rather than type IV or juxta-pararenal) versus 46.6% of men (p=0.001). Female patients presented with more challenging iliac accesses with at least one side considered hostile in 27.3% of the cases (vs 13.6% in male patients, p=0.039). Finally, women had significantly smaller visceral vessels. Women had significantly worse operative outcomes, with an 86.2% technical success rate versus 96.6% in the male population (p=0.016). No differences were recorded in terms of 30-day reinterventions between men and women. The 5-year estimate of freedom from late reintervention, according to Kaplan-Meier analysis, was 85.6% in men versus 81.6% in women (p=ns). No aneurysm-related death was recorded during follow-up (median observational time, 23 months [interquartile range, 7–45 months]). Conclusion: Women presented a significantly higher incidence of thoracoabdominal aneurysms, smaller visceral vessels, and more complex iliofemoral accesses, resulting in a significantly lower technical success after F/BEVAR. Further studies assessing sex-related differences are needed to properly determine the impact on outcomes and stratify procedural risks. Clinical Impact: Women are generally underrepresented in trials focusing on aortic aneurysms. Aiming to assess whether sex may affect outcomes after a complex endovascular aortic repair, a propensity score selection was applied to a total population of 596 patients receiving F/BEVAR aortic repair with the Cook platform, matching each treated female patient with a corresponding male patient. Women presented more frequently a thoracoabdominal aneurysm extent, smaller visceral vessels, and complex iliofemoral accesses, resulting in significantly worse operative outcomes, with an 86.2% technical success versus 96.6% (p=0.016). No differences were recorded in terms of short-term and mid-term reinterventions. According to these results, careful and critical assessment should be posed in case of female patients receiving complex aortic repair, especially regarding preoperative anatomical evaluation and clinical selection with appropriate surgical risk stratification

The new educational project Televascular Games during the Coronavirus Disease 2019 pandemic

Objective: To report methodology and first-year results of a new educational project called Televascular Games,” which took place during coronavirus disease 2019 pandemic. Methods: Complex aneurysmal aortic disease was discussed during a 2-hour competition webinar, according to three modalities. (1) Planning case competition (PCC): Two to four preoperative computed tomography angiography (CTA) scans of an already performed selected case were submitted for the competition. CTA scans were uploaded anonymously, without any reference to the center or the surgeon who performed the case. The competitor had to prepare a presentation of how he or she would have diagnosed, sized, planned, treated, and followed up the case, of the medical therapy and of the bail-out maneuvers. (2) Challenging case competition (CCC): The competitor elaborates a presentation of an already treated case concerning an aortic topic and discusses sizing, planning, treatment, possible bail-out maneuvers and obtained results. For the CCC and PCC, the competitors with the best score were preselected to present and discuss their plan during the webinars. (3) Quiz competition: Two to six CTA scans of already performed selected aortic cases were submitted for the competition. A quiz with multiple choice questions was answered by the competitors. The top four competitors were selected for the webinars and then they discussed the cases during the webinar. Finally, at the end of the case discussion, the effective case resolution and follow-up were shown. A final winner was voted via televoting, based on six preestablished criteria. The project was endorsed by different national and international societies. Results: Between October 2020 and December 2021, there were 12 Italian and 1 international webinars with 1695 participants overall (mean, 130; range, 86-177). Competitors were 54 years of age (mean, 27 years; range, 22-38 years). Two editions were CCCs, two quiz competitions, and nine PCCs. The reliability of the interobserver sizing of competitors was κ = 0.43 and κ = 0.62 for the proximal and distal sealing measurements respectively and very good (κ = 0.88-0.95) in the evaluation of orientation of the vessels, presence of angulations, calcifications, and thrombus. The sizing discrepancy resulted in a significant variability of the planning (κ = 0.45). The project ranked 9.6 on a 10-point rating scale by all the participants and competitors. Conclusions: The formula of gaming and collegial discussion of aortic cases herein reported has proved valid and attractive during coronavirus disease 2019 pandemic period. The variability of the results on sizing and planning suggested to confer with a second opinion, especially for less experienced surgeons

Fenestrated and Branched Endografts for Post-Dissection Thoraco-Abdominal Aneurysms: Results of a National Multicentre Study and Literature Review

Objective: Fenestrated and branched endografting (F/B-EVAR) has been proposed as an endovascular solution for chronic post-dissection thoraco-abdominal aneurysms (PD-TAAAs). The aim of this study was to analyse the experience of four high volume centres nationwide and the current available literature. Methods: Data on patients undergoing F/B-EVAR in four Italian academic centres between 2008 and 2019 were collected, and those from patients with PD-TAAAs were analysed retrospectively. Peri-operative morbidity and mortality were assessed as early outcomes. Survival, freedom from re-intervention (FFR), target visceral vessel (TVV) patency, and aortic remodelling were assessed as follow up outcomes. A MEDLINE search was performed for studies published from 2008 to 2020 reporting on F/B-EVAR in PD-TAAAs. Results: Among 351 patients who underwent F/B-EVAR for TAAAs, 37 (11%) had PD-TAAAs (Crawford's extent I–III: 35% – 95%). Overall, 135 TVVs (from true lumen 120; false lumen seven; both true and false lumen eight) were accommodated by fenestrations (96% – 71%) and branches (39% – 29%). Technical success (TS) was achieved in 34 (92%) cases with three failures due to endoleaks (Ia: 1; Ic: 1; III: 1). There were no 30 day deaths. No cases of permanent spinal cord ischaemia (SCI) were recorded and six (16%) patients suffered from transient deficits. Renal function worsening (eGFR < 30% than baseline) and pulmonary complications were reported in two (5%) and four (11%) cases, respectively. From the Kaplan–Meier analysis, three year survival, FFR, and TVV patency were 81%, 66%, and 97%, respectively. Radiological imaging was available for 30 (81%) patients at 12 months with complete false lumen thrombosis in 26 (87%). Two hundred and fifty-six patients were reported in seven published papers with TS, 30 day mortality, and SCI ranging from 99% to 100%, 0 to 6%, and 0 to 16%, respectively. The mean follow up ranged from 12 to 26 months, with estimated two year survival between 81% and 90% and a re-intervention rate between 19% and 53%. Conclusion: F/B-EVAR is effective to treat PD-TAAAs. A high re-intervention rate is necessary to complete the aneurysm exclusion and promote aortic remodelling successfully

Outcomes of “Anterior Versus Posterior Divisional Branches of the Hypogastric Artery as Distal Landing Zone for Iliac Branch Devices”: The International Multicentric R3OYAL Registry

Objective: The aim of this multicentric registry was to assess the outcomes of “anteRior versus posteRior divisional bRanches Of the hYpogastric artery as distAl landing zone for iLiac branch devices (R3OYAL).” Methods: The main exposure of interest for the purpose of this study was the internal iliac artery (IIA) divisional branch (anterior vs posterior) that was used as distal landing zone. Early endpoints included technical success and adverse events. Late endpoints included survival, primary/secondary IIA patency, and IIA branch instability. Results: A total of 171 patients were included in the study, of which 50 received bilateral implantation of iliac branch devices (IBDs). This resulted in a total of 221 incorporated IIAs included in the final analysis, of which 40 were anterior divisional branches and 181 were posterior divisional branches. Technical success was high in both groups (anterior division: 98% vs posterior division: 100%, P =.18). Occurrence of any adverse event was noted in 14% of patients in both groups (P = 1.0). The overall rate of freedom from the composite IBD branch instability did not show significant differences between patients receiving distal landing in the anterior or posterior division of the IIA at 3 years (79% vs 87%, log-rank test =.215). The 3-year estimates of IBD patency were significantly lower in patients who received distal landing in the anterior divisional branch than those who received distal landing in the posterior divisional branch (primary patency: 81% vs 96%, log-rank test =.009; secondary patency: 81% vs 97%, log-rank test <.001). Conclusions: The use of the anterior or posterior divisional branches of the IIA as distal landing zone for IBD implantation shows comparable profiles in terms of immediate technical success, perioperative safety, and side-branch instability up to 3 years. However, IBD patency at 3 years was higher when the distal landing zone was achieved within the posterior divisional branch of the IIA. Clinical Impact: The results from this large multicentric registry confirm that use of the anterior or posterior divisional branches of the internal iliac artery (IIA) as distal landing zone for implantation of iliac branch devices (IBD) shows comparable profiles of safety and feasibility, thereby allowing to extend the indications for endovascular repair of aorto-iliac aneurysms to cases with unsuitable anatomy within the IIA main trunk. Although mid-term rates of device durability and branch instability seem to be similar, the rates of primary and secondary IBD patency at three years was favored when the distal landing zone was achieved in the posterior divisional branch of the IIA

Mowat-Wilson syndrome: growth charts

Background Mowat-Wilson syndrome (MWS; OMIM #235730) is a genetic condition caused by heterozygous mutations or deletions of theZEB2gene. It is characterized by moderate-severe intellectual disability, epilepsy, Hirschsprung disease and multiple organ malformations of which congenital heart defects and urogenital anomalies are the most frequent ones. To date, a clear description of the physical development of MWS patients does not exist. The aim of this study is to provide up-to-date growth charts specific for infants and children with MWS. Charts for males and females aged from 0 to 16 years were generated using a total of 2865 measurements from 99 MWS patients of different ancestries. All data were collected through extensive collaborations with the Italian MWS association (AIMW) and the MWS Foundation. The GAMLSS package for the R statistical computing software was used to model the growth charts. Height, weight, body mass index (BMI) and head circumference were compared to those from standard international growth charts for healthy children. Results In newborns, weight and length were distributed as in the general population, while head circumference was slightly smaller, with an average below the 30th centile. Up to the age of 7 years, weight and height distribution was shifted to slightly lower values than in the general population; after that, the difference increased further, with 50% of the affected children below the 5th centile of the general population. BMI distribution was similar to that of non-affected children until the age of 7 years, at which point values in MWS children increased with a less steep slope, particularly in males. Microcephaly was sometimes present at birth, but in most cases it developed gradually during infancy; many children had a small head circumference, between the 3rd and the 10th centile, rather than being truly microcephalic (at least 2 SD below the mean). Most patients were of slender build. Conclusions These charts contribute to the understanding of the natural history of MWS and should assist pediatricians and other caregivers in providing optimal care to MWS individuals who show problems related to physical growth. This is the first study on growth in patients with MWS

Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme

Giant radio galaxies in the LOw-Frequency ARray Two-metre Sky Survey Bootes deep field

Simonte M, Andernach H, Brueggen M, Schwarz D, Prandoni I, Willis AG. Giant radio galaxies in the LOw-Frequency ARray Two-metre Sky Survey Bootes deep field. Monthly Notices of the Royal Astronomical Society . 2022;515(2):2032-2052.Giant radio galaxies (GRGs) are radio galaxies that have projected linear extents of more than 700 kpc or 1 Mpc, depending on definition. We have carried out a careful visual inspection in search of GRGs of the Bootes LOw-Frequency ARray Deep Field image at 150 MHz. We identified 74 GRGs with a projected size larger than 0.7 Mpc of which 38 are larger than 1 Mpc. The resulting GRG sky density is about 2.8 (1.43) GRGs per square degree for GRGs with linear size larger than 0.7 (1) Mpc. We studied their radio properties and the accretion state of the host galaxies using deep optical and infrared survey data and determined flux densities for these GRGs from available survey images at both 54 MHz and 1.4 GHz to obtain integrated radio spectral indices. We show the location of the GRGs in the P-D diagram. The accretion mode on to the central black holes of the GRG hosts is radiatively inefficient suggesting that the central engines are not undergoing massive accretion at the time of the emission. Interestingly, 14 out of 35 GRGs for which optical spectra are available show a moderate star-formation rate (10-100 M-circle dot yr(-1)). Based on the number density of optical galaxies taken from the Dark Energy Spectroscopic Instrument survey DR9 photometric redshift catalogue, we found no significant differences between the environments of GRGs and other radio galaxies, at least for redshift up to z = 0.7

Exploring the relation between turbulent velocity and density fluctuations in the stratified intracluster medium

Context. The dynamics of the intracluster medium (ICM) is affected by turbulence driven by several processes, such as mergers, accretion and feedback from active galactic nuclei. Aims. X-ray surface brightness fluctuations have been used to constrain turbulence in galaxy clusters. Here, we use simulations to further investigate the relation between gas density and turbulent velocity fluctuations, with a focus on the effect of the stratification of the ICM. Methods. In this work, we studied the turbulence driven by hierarchical accretion by analysing a sample of galaxy clusters simulated with the cosmological code ENZO. We used a fixed scale filtering approach to disentangle laminar from turbulent flows. Results. In dynamically perturbed galaxy clusters, we found a relation between the root mean square of density and velocity fluctuations, albeit with a different slope than previously reported. The Richardson number is a parameter that represents the ratio between turbulence and buoyancy, and we found that this variable has a strong dependence on the filtering scale. However, we could not detect any strong relation between the Richardson number and the logarithmic density fluctuations, in contrast to results by recent and more idealised simulations. In particular, we find a strong effect from radial accretion, which appears to be the main driver for the gas fluctuations. The ubiquitous radial bias in the dynamics of the ICM suggests that homogeneity and isotropy are not always valid assumptions, even if the turbulent spectra follow Kolmogorov’s scaling. Finally, we find that the slope of the velocity and density spectra are independent of cluster-centric radii