Systematic review and meta-analysis of outcomes after semi-conversion with graft preservation for failed endovascular aneurysm repair.

OBJECTIVE: The aim of this study was to evaluate the outcomes after semi-conversion (open conversion with graft preservation) after failed endovascular aneurysm repair (EVAR). The primary outcomes were 30-day mortality and semi-conversion failure. Secondary outcomes were 30-day major systemic complications, endoleak recurrence, reinterventions, and overall survival. METHODS: The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol was prospectively registered on PROSPERO (CRD42023421153). All studies reporting the outcomes of semi-conversions for failed EVAR were eligible for inclusion. Quality assessment was performed using the Methodological Index for Non-Randomized Studies (MINORS) tool. A random effects meta-regression of proportions was conducted using the double arcsine-Tukey transformation, given the frequent zero event rate in the primary outcome. Heterogeneity was assessed with the I2 statistic. RESULTS: Eight studies were included in the review after full text screening. A total of 196 patients underwent semi-conversion at a mean time from EVAR of 47.4 months, 68.9% in an elective setting. Mean age at conversion was 78.1 years, and the main indication was isolated endoleak type II (70.1% of cases). Aortic clamping was not necessary in 92.3% of semi-conversions; the aortic sac was opened in 96.1% of cases; in 93.3% of cases, ligation/suture of one or more culprit arteries were performed; and aortic neck banding was executed in 29.2%. At 30 days from surgery, the pooled mortality and the major systemic complications rates were 5.3% (I2 = 24.9%) and 13.4% (I2 = 54.3%), respectively. At follow-up, endoleak recurred after 12.6% semi-conversions (I2 = 83.2%), and the rate of reinterventions was 7% (I2 = 50.1%); the semi-conversion failure rate was 5.5% (I2 = 54.1%), and the overall survival was 84.6% (I2 = 33.3%). CONCLUSIONS: Semi-conversions have acceptable 30-day mortality rates, but the early and mid-term risks of complications, reinterventions, ruptures, and infections are not negligible. This procedure might be an alternative to complete or partial graft explant in patients whom aortic cross-clamping is not ideal.

Editor's Choice - Comparison of Open Surgery and Endovascular Techniques for Juxtarenal and Complex Neck Aortic Aneurysms: The UK COMPlex AneurySm Study (UK-COMPASS) - Peri-operative and Midterm Outcomes.

OBJECTIVE: Treatment of juxtarenal and complex neck abdominal aortic aneurysms (AAAs) is now commonly by endovascular rather than open surgical repair (OSR). Published comparisons show poor validity and scientific precision. UK-COMPASS is a comparative cohort study of endovascular treatments vs. OSR for patients with an AAA unsuitable for standard on label endovascular aneurysm repair (EVAR). METHODS: All procedures for AAA in England (November 2017 to October 2019) were identified, AAA anatomy assessed in a Corelab, peri-operative risk scores determined, and propensity scoring used to identify patients suitable for either endovascular treatment or OSR. Patients were stratified by aneurysm neck length (0 - 4 mm, 5 - 9 mm, or ≥ 10 mm) and operative risk; the highest quartile was considered high risk and the remainder standard risk. Death was the primary outcome measure. Endovascular treatments included fenestrated EVAR (FEVAR) and off label standard EVAR (± adjuncts). RESULTS: Among 8 994 patients, 2 757 had AAAs that were juxtarenal, short neck, or complex neck in morphology. Propensity score stratification and adjustment method comparisons included 1 916 patients. Widespread off label use of standard EVAR devices was noted (35.6% of patients). The adjusted peri-operative mortality rate was 2.9%, lower for EVAR (1.2%; p = .001) and FEVAR (2.2%; p = .001) than OSR (4.5%). In standard risk patients with a 0 - 4 mm neck, the mortality rate was 7.4% following OSR and 2.3% following FEVAR. Differences were smaller for patients with a neck length ≥ 5 mm: 2.1% OSR vs. 1.0% FEVAR. At 3.5 years of follow up, the overall mortality rate was 20.7% in the whole study population, higher following FEVAR (27.6%) and EVAR (25.2%) than after OSR (14.2%). However, in the 0 - 4 mm neck subgroup, overall survival remained equivalent. The aneurysm related mortality rate was equivalent between treatments, but re-intervention was more common after EVAR and FEVAR than OSR. CONCLUSION: FEVAR proves notably safer than OSR in the peri-operative period for juxtarenal aneurysms (0 - 4 mm neck length), with comparable midterm survival. For patients with short neck (5 - 9 mm) and complex neck (≥ 10 mm) AAAs, overall survival was worse in endovascularly treated patients compared with OSR despite relative peri-operative safety. This warrants further research and a re-appraisal of the current clinical application of endovascular strategies, particularly in patients with poor general survival outlook owing to comorbidity and age.

Selective neural inhibition via photobiomodulation alleviates behavioral hypersensitivity associated with small sensory fiber activation.

OBJECTIVE: Photobiomodulation at higher irradiances has great potential as a pain-alleviating method that selectively inhibits small diameter nerve fibers and corresponding sensory experiences, such as nociception and heat sensation. The longevity and magnitude of these effects as a function of laser irradiation parameters at the nerve was explored. METHODS: In a rodent chronic pain model (spared nerve injury-SNI), light was applied directly at the sural nerve with four delivery schemes: two irradiance levels (7.64 and 2.55 W/cm2 ) for two durations each, corresponding to either 4.8 or 14.4 J total energy, and the effect on sensory hypersensitivities was evaluated. RESULTS: At emitter irradiances of 7.64 W/cm2 (for 240 s), 2.55 W/cm2 (for 720 s), and 7.64 W/cm2 (for 80 s) the heat hypersensitivity was relieved the day following photobiomodulation (PBM) treatment by 37 ± 8.1% (statistically significant, p < 0.001), 26% ± 6% (p = 0.072), and 28 ± 6.1% (statistically significant, p = 0.032), respectively, and all three treatments reduced the hypersensitivity over the course of the experiment (13 days) at a statistically significant level (mixed-design analysis of variance, p < 0.05). The increases in tissue temperature (5.3 ± 1.0 and 1.3 ± 0.4°C from 33.3°C for the higher and lower power densities, respectively) at the neural target were well below those typically associated with permanent action potential disruption. CONCLUSIONS: The data from this study support the use of direct PBM on nerves of interest to reduce sensitivities associated with small-diameter fiber activity.

Direct Photobiomodulation Therapy on the Sciatic Nerve Significantly Attenuates Acute Nociceptive Sensitivity Without Affecting Motor Output.

OBJECTIVES: Pharmacologic pain treatments lack specific targeting and often produce unwanted side effects (eg, addiction, additional hyperalgesia). We previously established that the direct application of laser irradiation (direct photobiomodulation [PBM]) of the sural nerve reduces thermal hypersensitivity in a rodent model of chronic pain, but not mechanical hypersensitivity. These observations were consistent with a selective reduction in the small-diameter fiber contribution to electrophysiologically measured evoked response after direct PBM of a sensory nerve (saphenous). However, to our knowledge, direct application of laser irradiation has never been performed in an animal model of acute nociceptive pain or on a mixed nerve in which sensory and motor outcomes can be observed. MATERIALS AND METHODS: In this study, we describe the effects of direct application of laser irradiation (808 nm, 60 mW, 4 minutes) on a mixed nerve (sciatic nerve) in an acute nociceptive pain model (intradermal capsaicin injection) in rats over the course of two weeks. To investigate whether laser irradiation of a mixed nerve alters motor function, in separate experiments, we applied laser irradiation to the sciatic nerve (using the same parameters as in the chronic pain experiments), and force generation of the gastrocnemius was measured. RESULTS: Capsaicin-induced hypersensitivities to mechanical (pin prick) and thermal (Hargreaves) noxious stimuli, associated with Aδ- and C-fibers, showed a maximal reduction of 70% and 56.2%, respectively, by direct PBM, when compared with a control group (vehicle injection, no PBM) on the same day. This reduction was determined to be significant using a mixed-design analysis of variance with a p value < 0.05. Force generation remained unchanged for up to 120 minutes after laser irradiation. In summary, direct PBM selectively inhibits C- and Aδ-fiber transmission while leaving Aɑ-, Aß-, and motor-fiber activity intact. CONCLUSIONS: These results, in conjunction with our previous analyses of laser irradiation effects on the sural nerve in a chronic spared nerve injury pain model, suggest that direct PBM is a promising candidate for treating pain induced by small-diameter fiber activity.

Slide Over: Advances in Slide-Free Optical Microscopy as Drivers of Diagnostic Pathology.

Conventional analysis using clinical histopathology is based on bright-field microscopy of thinly sliced tissue specimens. Although bright-field microscopy is a simple and robust method of examining microscope slides, the preparation of the slides needed is a lengthy and labor-intensive process. Slide-free histopathology, however, uses direct imaging of intact, minimally processed tissue samples using advanced optical-imaging systems, bypassing the extended workflow now required for the preparation of tissue sections. This article explains the technical basis of slide-free microscopy, reviews common slide-free optical microscopy techniques, and discusses the opportunities and challenges involved in clinical implementation.

Selective Infrared Neural Inhibition Can Be Reproduced by Resistive Heating.

OBJECTIVES: Small-diameter afferent axons carry various sensory signals that are critical for vital physiological conditions but sometimes contribute to pathologies. Infrared (IR) neural inhibition (INI) can induce selective heat block of small-diameter axons, which holds potential for translational applications such as pain management. Previous research suggested that IR-heating-induced acceleration of voltage-gated potassium channel kinetics is the mechanism for INI. Therefore, we hypothesized that other heating methods, such as resistive heating (RH) in a cuff, could reproduce the selective inhibition observed in INI. MATERIALS AND METHODS: We conducted ex vivo nerve-heating experiments on pleural-abdominal connective nerves of Aplysia californica using both IR and RH. We fabricated a transparent silicone nerve cuff for simultaneous IR heating, RH, and temperature measurements. Temperature elevations (ΔT) on the nerve surface were recorded for both heating modalities, which were tested over a range of power levels that cover a similar ΔT range. We recorded electrically evoked compound action potentials (CAPs) and segmented them into fast and slow subcomponents on the basis of conduction velocity differences between the large and small-diameter axonal subpopulations. We calculated the normalized inhibition strength and inhibition selectivity index on the basis of the rectified area under the curve of each subpopulation. RESULTS: INI and RH showed a similar selective inhibition effect on CAP subcomponents for slow-conducting axons, confirmed by the inhibition probability vs ΔT dose-response curve based on approximately 2000 CAP measurements. The inhibition selectivity indexes of the two heating modalities were similar across six nerves. RH only required half the total electrical power required by INI to achieve a similar ΔT. SIGNIFICANCE: We show that selective INI can be reproduced by other heating modalities such as RH. RH, because of its high energy efficiency and simple design, can be a good candidate for future implantable neural interface designs.

Two single-axis scanners make a virtual gimbaled scanner.

A 2D scan generated from two single-axis scanning mirrors often has the beam steered about two distant axes that lead to scan artifacts, such as displacement jitters, telecentric errors, and spot variations. Previously, this problem has been addressed with complicated optical and mechanical designs, such as 4f relays and gimbaled mechanics, which ultimately limit the performance of the system. Here, we show that two single-axis scanners alone can produce a 2D scanning pattern nearly identical to a single-pivot gimbaled scanner through an apparently previously undiscovered simple geometry. This finding broadens the design parameter space of beam steering applications.

Mistakes strengthen the temporal binding effect in the context of goal-directed actions.

Temporal binding is an illusion in which the temporal interval between two events appears compressed. In the context of intentional actions, this effect is observed as a compression of the perceived interval between these actions and their causal outcomes. This 'intentional binding effect' has been used to investigate the Sense of Agency, which is the experience of intentionally causing an outcome through volitional action. Intentional binding is reduced for negative outcomes such as error feedback, but the role of mistakes (e.g., errors of commission) for binding and agency has not been extensively studied. In our study, participants played a virtual game in which they attempted to 'splat' (hit) visual stimuli that looked like coloured bugs, using mouse clicks. On some trials, stimulus colours changed unpredictably immediately before actions were made, sometimes inducing mistakes. Actions were thus clearly identifiable as mistakes at the time of their onset before any outcome feedback had been provided. Participants reported shorter action-outcome intervals when stimuli changed, but only when this change caused a mistake according to the game's rules. This suggests that intentional binding is strengthened by errors of commission. We discuss how this effect may be accounted for by agency itself and via more general processes such as changes in arousal.

Effects of high intensity interval training on cardiorespiratory fitness and salivary levels of IL-8, IL-1ra, and IP-10 in adults with asthma and non-asthma controls.

OBJECTIVE: The purpose of this study was to determine whether high intensity interval training (HIIT) would lead to improvements in 1) maximal VO2, VE, VE/VCO2, and VE/MVV, and/or 2) resting salivary concentrations of pro-inflammatory markers Interleukin (IL-8), interferon-gamma-inducible-protein (CXCL10/IP-10)) and anti-inflammatory marker IL-1 receptor antagonist (IL-1ra) in adults with well-controlled asthma compared to non-asthma controls. METHODS: Participants completed a maximal exercise test at the beginning (T1) and end (T2) of a 6-week HIIT intervention; saliva samples were obtained at the beginning and 30 min following the first (T1) and last (T2) exercise session. RESULTS: Adults with asthma (n = 20; age: 21.4 ± 2.4 years) and non-asthma controls (n = 12; age: 22.5 ± 3.4 years) completed the intervention. VO2max increased from T1 to T2 in both groups (asthma T1 32.9 ± 8, T2 38.6 ± 8.2 ml/kg/min; controls T1 34.5 ± 11.8, T2 38.9 ± 12.3 ml/kg/min). VEmax also increased in both groups (asthma T1 97.7, T2 110.8 units, p < 0.001, hp2 = <0.04; control T1 106.3, T2 118.1, p < 0.001, hp2 0.02). An increase in VE/VCO2 (F(1, 10)=22.11, p = 0.001) and VE/MVV (F(1, 10) = 111.30, p < 0.001) was observed in the control group; no differences were observed in the asthma group. No differences in IL-8 or IL-1ra were observed between groups. In the asthma group, resting salivary IP-10 concentrations significantly decreased from T1 (0.025 pg/ug protein) to T2 (0.015 pg/ug protein, p = 0.039, hp2 = 0.3 (moderate effect)). CONCLUSION: A 6-week HIIT intervention led to a similar increase in VO2max and VEmax in those with and without asthma, and a decrease in resting salivary IP-10 levels among adults with asthma.

Prenatal ethanol exposure impairs the conduction delay at the atrioventricular junction in the looping heart.

The etiology of ethanol-related congenital heart defects has been the focus of much study, but most research has concentrated on cellular and molecular mechanisms. We have shown with optical coherence tomography (OCT) that ethanol exposure led to increased retrograde flow and smaller atrioventricular (AV) cushions compared with controls. Since AV cushions play a role in patterning the conduction delay at the atrioventricular junction (AVJ), this study aims to investigate whether ethanol exposure alters the AVJ conduction in early looping hearts and whether this alteration is related to the decreased cushion size. Quail embryos were exposed to a single dose of ethanol at gastrulation, and Hamburger-Hamilton stage 19-20 hearts were dissected for imaging. Cardiac conduction was measured using an optical mapping microscope and we imaged the endocardial cushions using OCT. Our results showed that, compared with controls, ethanol-exposed embryos exhibited abnormally fast AVJ conduction and reduced cushion size. However, this increased conduction velocity (CV) did not strictly correlate with decreased cushion volume and thickness. By matching the CV map to the cushion-size map along the inflow heart tube, we found that the slowest conduction location was consistently at the atrial side of the AVJ, which had the thinner cushions, not at the thickest cushion location at the ventricular side as expected. Our findings reveal regional differences in the AVJ myocardium even at this early stage in heart development. These findings reveal the early steps leading to the heterogeneity and complexity of conduction at the mature AVJ, a site where arrhythmias can be initiated.NEW & NOTEWORTHY To the best of our knowledge, this is the first study investigating the impact of ethanol exposure on the early cardiac conduction system. Our results showed that ethanol-exposed embryos exhibited abnormally fast atrioventricular conduction. In addition, our findings, in CV measurements and endocardial cushion thickness, reveal regional differences in the AVJ myocardium even at this early stage in heart development, suggesting that the differentiation and maturation at this site are complex and warrant further studies.

Four-year results of the Bolton relay proximal scallop endograft in the management of thoracic and thoracoabdominal aortic pathology with unfavorable proximal landing zone.

BACKGROUND: Thoracic endovascular aortic repair with a scallop design (scallop-TEVAR) is a useful treatment strategy to extend the proximal landing zone (PLZ), while maintaining perfusion to one or more of the supra-aortic trunks (SATs) when treating aortic pathology with an unfavorable PLZ. The durability of this approach with the Bolton Relay scallop endograft (Terumo Aortic, Sunrise, Fla) has not been established. METHODS: A retrospective review of prospectively collected data on consecutive patients that received scallop-TEVAR in zones 0 to 2 at a tertiary aortic unit was undertaken. The main outcome was durability, characterized by survival estimates, freedom from reintervention to the thoracic aorta and PLZ, migration and aneurysm sac regression. RESULTS: Between 2009 and 2019, 38 patients (71% male; median age, 70 years) underwent scallop-TEVAR for thoracic aortic pathology (n = 28, 74%) or as a part of thoracoabdominal aneurysm repair (n = 10 [26%]). The use of scallop-TEVAR significantly extended the PLZ (median, 5 mm preoperative PLZ vs 26 mm extended PLZ; P = .0001). A total of 41 SATs were perfused with a scallop, including the left subclavian artery (n = 25), left common carotid artery (n = 6), neo/innominate artery (n = 4), left subclavian artery, and vertebral artery (n = 1), innominate artery, and left common carotid artery (n = 2) in conjunction with 15 extra-anatomical bypasses. The PLZ was at Ishimaru zone 0 and 1 in 6 cases (16%), respectively, and zone 2 in 26 cases (68%). Technical success was 98%. The 30-day mortality was 5% (2/38; 1 death from myocardial infarction and 1 from multiorgan failure). A minor stroke occurred in three patients (8%) and temporary spinal cord ischemia in two patients (5%). The median follow-up was 4.5 years (range, 0-10.53 years) during which two patients (5%) developed type Ia endoleak and required intervention to the PLZ (one from device-related migration and one from disease progression). All-cause and aorta-related survival were 72% and 85% and freedom from thoracic and PLZ reintervention was 92% and 97%, respectively. There were no cases of early or late thoracic aortic rupture, retrograde type A aortic dissection or SAT occlusion. CONCLUSIONS: Scallop-TEVAR offers a less invasive treatment option to extend the seal zone in selected patients with an unfavorable PLZ, allowing for a durable repair in terms of overall survival and reintervention. Periprocedural stroke remains a principle concern.

Glutathione Protects the Developing Heart from Defects and Global DNA Hypomethylation Induced by Prenatal Alcohol Exposure.

BACKGROUND: Fetal alcohol spectrum disorder (FASD) is caused by prenatal alcohol exposure (PAE), the intake of ethanol (C2 H5 OH) during pregnancy. Features of FASD cover a range of structural and functional defects including congenital heart defects (CHDs). Folic acid and choline, contributors of methyl groups to one-carbon metabolism (OCM), prevent CHDs in humans. Using our avian model of FASD, we have previously reported that betaine, another methyl donor downstream of choline, prevents CHDs. The CHD preventions are substantial but incomplete. Ethanol causes oxidative stress as well as depleting methyl groups for OCM to support DNA methylation and other epigenetic alterations. To identify more compounds that can safely and effectively prevent CHDs and other effects of PAE, we tested glutathione (GSH), a compound that regulates OCM and is known as a "master antioxidant." METHODS/RESULTS: Quail embryos injected with a single dose of ethanol at gastrulation exhibited congenital defects including CHDs similar to those identified in FASD individuals. GSH injected simultaneously with ethanol not only prevented CHDs, but also improved survival and prevented other PAE-induced defects. Assays of hearts at 8 days (HH stage 34) of quail development, when the heart normally has developed 4-chambers, showed that this single dose of PAE reduced global DNA methylation. GSH supplementation concurrent with PAE normalized global DNA methylation levels. The same assays performed on quail hearts at 3 days (HH stage 19-20) of development, showed no difference in global DNA methylation between controls, ethanol-treated, GSH alone, and GSH plus ethanol-treated cohorts. CONCLUSIONS: GSH supplementation shows promise to inhibit effects of PAE by improving survival, reducing the incidence of morphological defects including CHDs, and preventing global hypomethylation of DNA in heart tissues.

Exploring the relationship between perceived Action-Outcome distance and Agency: Evidence from temporal binding.

Intentional actions are usually accompanied by a sense of agency (SoA), along with a perceived shortening of action-outcome intervals known as the intentional binding (IB) effect. This is at least partly associated with the perceived strength of action-outcome relationships, which have been described in terms of distance (e.g., a 'distancing effect'). Given that actions in the modern world are increasingly distant from their outcomes, the current study aimed to explore the effect of perceived spatial distance on the strength of IB. Participants voluntarily triggered, or passively observed, a circle on a background that was either flat or appeared three-dimensional, and estimated action-outcome delays. Depth cues modified the circle's perceived distance while the circle itself did not change. When viewed on a forced-perspective background, interval estimates increased with apparent distance, but only when outcomes were caused by intentional actions. This suggests that agency is reduced for outcomes that appear further away.

An investigation of "We" agency in co-operative joint actions.

Sense of agency refers to the sense that I am controlling an action or outcome, and is associated with a perceived compression of the temporal interval between these events known as intentional binding (IB). Though most IB studies focus on individually performed actions, some reveal the existence of shared implicit agency among joint actors, suggesting the formation of a shared "we" identity that may be sensitive to the intentions and actions of all actors. While current understanding of this shared agentic identity is far from clear, the present study used variants of the IB paradigm involving truly co-operative actions to investigate (1) the relative strength of individual and joint agency, and (2) whether different complementary roles modulate the sense of agency among joint actors. Experiment 1 compared the strength of agency for actions performed alone or with a partner, by instructing pairs of participants to press a key simultaneously to produce an auditory tone. Here, binding was weaker when performing jointly, but this may have been influenced by the demands of temporally co-ordinating actions. Experiment 2 removed these task demands by implementing joint actions that were not identical but complementary, and assessed the impact of varying roles (moving versus clicking a mouse) on agency. Here, binding was similar for independent and joint actions, and across all roles. These results support the notion of a shared "we" identity, suggesting that the joint sense of agency is as strong as individual agency and represents the intentions and actions of all co-actors.

Short- and long-term outcomes in isolated penetrating aortic ulcer disease.

BACKGROUND: The optimum management of isolated penetrating aortic ulceration (PAU), with no associated intramural hematoma or aortic dissection is not clear. We evaluate the short- and long-term outcomes in isolated PAU to better inform management strategies. METHODS: We conducted a retrospective review of 43 consecutive patients (mean age, 72.2 years; 26 men) with isolated PAU (excluding intramural hematoma/aortic dissection) managed at a single tertiary vascular unit between November 2007 and April 2019. Twenty-one percent had PAU of the arch, 62% of the thoracic aorta, and 17% of the abdominal aorta. Conservative and surgical groups were analyzed separately. Primary outcomes included mortality, PAU progression, and interventional complications. RESULTS: Initially, 67% of patients (29/43) were managed conservatively; they had significantly smaller PAU neck widths (P = .04), PAU depths (P = .004), and lower rates of associated aneurysmal change (P = .004) compared with those initially requiring surgery. Four patients (4/29) initially managed conservatively eventually required surgical management at a mean time interval of 49.75 months (range, 9.03-104.33 months) primarily owing to aneurysmal degeneration. Initially, 33% of patients (14/43) underwent surgical management; 7 of the 14 procedures were urgent. Of the 18 patients, 17 eventually managed with surgical intervention had an endovascular repair; 2 of the 17 endovascular cases involved supra-aortic debranching, six used scalloped, fenestrated, or chimney stents. The overall long-term mortality was 30% (mean follow-up, 48 months; range, 0-136 months) with no significant difference between the conservatively and surgically managed groups (P = .98). No aortic-related deaths were documented during follow-up in those managed conservatively. There was no in-hospital mortality after surgical repair. Of these 18 patients, two required reintervention within 30 days for type I or III endoleaks. Among the 18 patients, seven died during follow-up (mean survival, 90.24 months; range, 66.48-113.88) with 1 of the 18 having a confirmed aortic-related death. CONCLUSIONS: Isolated, asymptomatic, small PAUs may be safely managed conservatively with regular surveillance. Those with high-risk features or aneurysmal progression require complex strategies for successful treatment with acceptable long-term survival.

Volatiles of High-Elevation Five-Needle Pines: Chemical Signatures through Ratios and Insight into Insect and Pathogen Resistance.

High-elevation five-needle pine trees are a group of Pinus species in the subgenus Strobus that occur at the edges of plant growth near the alpine tree line. These species are ecologically very important and are also threatened by climate-driven insect outbreaks and an exotic pathogen. Volatile organic compounds (VOCs) play central roles in the environmental adaptation of plants and in their defense against insects and pathogens. For example, the VOCs emitted by some high-elevation five-needle pine species attract female, tree-killing mountain pine beetles (MPB, Dendroctonus ponderosae) in the pioneering phase whereas VOCs from other species strongly repel this foremost herbivore, but the mechanism is unknown. We collected and compared headspace VOCs from foliage of eight species of high-elevation five-needle pines in Europe and North America. Overall, VOCs differed quantitatively among species with few qualitative differences. Despite species emitting essentially the same compounds, Random Forest analysis correctly classified 117 of the 126 trees sampled by using VOCs and identified the most important compounds for species classification and for separating species resistant from those susceptible to MPB or white pine blister rust (Cronartium ribicola). These VOC 'fingerprints' resulted largely from species emitting distinctive ratios of compounds, rather than through presence of species-specific compounds. Importantly, these Pinus species vary greatly in resistance to the main herbivore (MPB) and pathogen (white pine blister rust) causing tree mortality. Thus, these findings provide insights and should guide research into understanding resistance and in developing tools to manage these important trees. For instance, studies into the functions of five-needle pine VOCs in defense against abiotic or biotic stressors should focus on blend ratios rather than on individual compounds.

Identifying the Role of Block Length in Neural Heat Block to Reduce Temperatures During Infrared Neural Inhibition.

BACKGROUND AND OBJECTIVES: The objective of this study is to assess the hypothesis that the length of axon heated, defined here as block length (BL), affects the temperature required for thermal inhibition of action potential propagation applied using laser heating. The presence of such a phenomenon has implications for how this technique, called infrared neural inhibition (INI), may be applied in a clinically safe manner since it suggests that temperatures required for therapy may be reduced through the proper spatial application of light. Here, we validate the presence of this phenomenon by assessing how the peak temperatures during INI are reduced when two different BLs are applied using irradiation from either one or two adjacent optical fibers. STUDY DESIGN/MATERIALS AND METHODS: Assessment of the role of BL was carried out over two phases. First, a computational proof of concept was performed in the neural conduction simulation environment, NEURON, simulating the response of action potentials to increased temperatures applied at different full-width at half-maxima (FWHM) along axons. Second, ex vivo validation of these predictions was performed by measuring the radiant exposure, peak temperature rise, and FWHM of heat distributions associated with INI from one or two adjacent optical fibers. Electrophysiological assessment of radiant exposures at inhibition threshold were carried out in ex vivo Aplysia californica (sea slug) pleural abdominal nerves ( n = 6), an invertebrate with unmyelinated axons. Measurement of the maximum temperature rise required for induced heat block was performed in a water bath using a fine wire thermocouple. Finally, magnetic resonance thermometry (MRT) was performed on a nerve immersed in saline to assess the elevated temperature distribution at these radiant exposures. RESULTS: Computational modeling in NEURON provided a theoretical proof of concept that the BL is an important factor contributing to the peak temperature required during neural heat block, predicting a 11.7% reduction in temperature rise when the FWHM along an axon is increased by 42.9%. Experimental validation showed that, when using two adjacent fibers instead of one, a 38.5 ± 2.2% (mean ± standard error of the mean) reduction in radiant exposure per pulse per fiber threshold at the fiber output (P = 7.3E-6) is measured, resulting in a reduction in peak temperature rise under each fiber of 23.5 ± 2.1% ( P = 9.3E-5) and 15.0 ± 2.4% ( P = 1.4E-3) and an increase in the FWHM of heating by 37.7 ± 6.4% ( P = 1E-3), 68.4 ± 5.2% ( P = 2.4E-5), and 51.9 ± 9.9% ( P = 1.7E-3) in three MRT slices. CONCLUSIONS: This study provides the first experimental evidence for a phenomenon during the heat block in which the temperature for inhibition is dependent on the BL. While more work is needed to further reduce the temperature during INI, the results highlight that spatial application of the temperature rise during INI must be considered. Optimized implementation of INI may leverage this cellular response to provide optical modulation of neural signals with lower temperatures over greater time periods, which may increase the utility of the technique for laboratory and clinical use. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Thoracic endovascular stent graft repair for ascending aortic diseases.

OBJECTIVES: We describe the preliminary results of thoracic endovascular aortic repair (TEVAR) in a group of patients with ascending aortic disease from the Global Registry for Endovascular Aortic Treatment (GREAT). METHODS: We identified TEVAR performed for diseases truly originating from the ascending aorta. Between July 2011 and May 2015, 5014 patients were enrolled; six (0.12%) were identified and included in the analysis. One further patient was withdrawn from the study due to lack of a signed consent form. Patients having a "zone 0" proximal landing zone reported for their TEVAR without the presence of an ascending aortic disease were not included. Reinterventions of previous open and endovascular repair were also excluded. RESULTS: Three males and three females were treated. Mean age was 69 years ± 10 years (range, 58-83 years). Indication for TEVAR was atherosclerotic aneurysm (n = 4; ruptured, n = 1), complicated type A dissection (n = 1, rupture), and pseudoaneurysm (n = 1). Mean maximum aortic lesion diameter was 60 mm 14 (range, 39-77 mm). Urgent intervention was performed in three (50%) cases. Primary clinical success was 100%. There was no TEVAR-related in-hospital mortality. Open conversion was never required. Complication such as cerebrovascular accidents, valve impairment, or myocardial infarction did not occur. All patients were discharged home alive. No patient was lost at a median follow-up of 26 months (range, 16-72 months). During the follow-up, no patient died and ongoing primary clinical success was maintained in all patients. Reintervention was never required; endoleaks, migrations, fractures, or ruptures were not observed. CONCLUSIONS: Preliminary "real-world" experience of ascending TEVAR shows satisfactory outcomes at short-term follow-up. Although concerns remain for "off-label" use of standard devices, TEVAR-related complications were not observed. Longer follow-up data are expected to confirm durability of these results.

Short-term and Midterm Results of Fenestrated Anaconda Endograft in Patients with Previous Endovascular Aneurysm Repair.

PURPOSE: To review short-term and midterm results of the fenestrated Anaconda stent graft in management of patients with pre-existing endovascular aortic stent graft and persistent type 1a endoleak. MATERIALS AND METHODS: This single-center retrospective study assessed all consecutive patients with type 1a endoleak and pre-existing endovascular aneurysm repair (EVAR) treated with fenestrated Anaconda stent grafts. Ten patients (9 males; mean age 78 y) with mean follow-up of 22.4 months ± 13 were included. Average aneurysm size was 80.1 mm (range, 62-101 mm). Mean time for conversion to fenestrated EVAR following original EVAR was 53.7 months (range, 22-101 months; median 54 months). Technical and clinical success; anatomic features, including aortic tortuosity, side vessel angulation, and stenosis; complications; and reinterventions were recorded. RESULTS: The technical success rate was 90%. There was no open conversion and no 30-day mortality, leading to a clinical success rate of 100%. Five of 10 patients demonstrated an aortic tortuosity index of grade 2 or 3. Additional hostile anatomy that made side vessel catheterization challenging was observed in 15 vessels (45%) with a stenosis of ≥ 50% (related to atherosclerotic disease or struts of indwelling prosthesis) and 21 vessels (66%) with ≤ 70° angulation. Two reinterventions, renal artery stent angioplasty and renal artery covered stent extension, were observed at 2 and 13 months. CONCLUSIONS: Use of the fenestrated Anaconda endograft in patients with type 1a endoleaks following previous EVAR is safe, feasible, and offers some technical features that facilitate overcoming certain anatomic difficulties.

Removing vessel constriction on the embryonic heart results in changes in valve gene expression, morphology, and hemodynamics.

BACKGROUND: The formation of healthy heart valves throughout embryonic development is dependent on both genetic and epigenetic factors. Hemodynamic stimuli are important epigenetic regulators of valvulogenesis, but the resultant molecular pathways that control valve development are poorly understood. Here we describe how the heart and valves recover from the removal of a partial constriction (banding) of the OFT/ventricle junction (OVJ) that temporarily alters blood flow velocity through the embryonic chicken heart (HH stage 16/17). Recovery is described in terms of 24- and 48-hr gene expression, morphology, and OVJ hemodynamics. RESULTS: Collectively, these studies show that after 24 hr of recovery, important epithelial-mesenchymal transformation (EMT) genes TGFßRIII and Cadherin 11 (CDH11) transcript levels normalize return to control levels, in contrast to Periostin and TGFß,3 which remain altered. In addition, after 48 hr of recovery, TGFß3 and CDH11 transcript levels remain normalized, whereas TGFßRIII and Periostin are down-regulated. Analyses of OFT cushion volumes in the hearts show significant changes, as does the ratio of cushion to cell volume at 24 hr post band removal (PBR). Morphologically, the hearts show visible alteration following band removal when compared to their control age-matched counterparts. CONCLUSIONS: Although some aspects of the genetic/cellular profiles affected by altered hemodynamics seem to be reversed, not all gene expression and cardiac growth normalize following 48 hr of band removal. Developmental Dynamics 247:531-541, 2018. © 2017 Wiley Periodicals, Inc.