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Objective: Patients with peripheral arterial disease (PAD) have a significant risk of myocardial infarction and death secondary to concomitant coronary artery disease (CAD). This is particularly true in patients with critical limb-threatening ischemia (CLTI) who exceed a 20% mortality rate at 6 months despite standard treatment with risk factor modification. Although systematic preoperative coronary testing is not recommended for patients with PAD without cardiac symptoms, the clinical manifestations of CAD are often muted in patients with CLTI due to poor mobility and activity intolerance. Thus, the true incidence and impact of "silent" CAD in a CLTI cohort is unknown. This study aims to determine the prevalence of ischemia-producing coronary artery stenosis in a CLTI cohort using coronary computed tomography angiography (cCTA) and computed tomography (CT)-derived fractional flow reserve (FFR CT ), a noninvasive imaging modality that has shown significant correlation to cardiac catheterization in the detection of clinically relevant coronary ischemia., Methods: Patients presenting with newly diagnosed CLTI at our institution from May 2020 to April 2021 were screened for underlying CAD. Included subjects had no known history of CAD, no cardiac symptoms, and no anginal equivalent complaints at presentation. Patients underwent cCTA and FFR CT evaluation and were classified by the anatomic location and severity of CAD. Significant coronary ischemia was defined as FFR CT ≤0.80 distal to a >30% coronary stenosis, and severe coronary ischemia was documented at FFR CT ≤0.75, consistent with established guidelines., Results: A total of 170 patients with CLTI were screened; 65 patients (38.2%) had no coronary symptoms and met all inclusion/exclusion criteria. Twenty-four patients (31.2%) completed cCTA and FFR CT evaluation. Forty-one patients have yet to complete testing secondary to socioeconomic factors (insurance denial, transportation inaccessibility, testing availability, etc). The mean age of included subjects was 65.4 ± 7.0 years, and 15 (62.5%) were male. Patients presented with ischemic rest pain (n = 7; 29.1%), minor tissue loss (n = 14; 58.3%) or major tissue loss (n = 3; 12.5%). Significant (≥50%) coronary artery stenosis was noted on cCTA in 19 of 24 patients (79%). Significant left main coronary artery stenosis was identified in two patients (10%). When analyzed with FFR CT , 17 patients (71%) had hemodynamically significant coronary ischemia (FFR CT ≤0.8), and 54% (n = 13) had lesion-specific severe coronary ischemia (FFR CT ≤0.75). The mean FFR CT in patients with coronary ischemia was 0.70 ± 0.07. Multi-vessel disease pattern was present in 53% (n = 9) of patients with significant coronary stenosis., Conclusions: The use of cCTA-derived fractional flow reserve demonstrates a significant percentage of patients with CLTI have silent (asymptomatic) coronary ischemia. More than one-half of these patients have lesion-specific severe ischemia, which may be associated with increased mortality when treated solely with risk factor modification. cCTA and FFR CT diagnosis of significant coronary ischemia has the potential to improve cardiac care, perioperative morbidity, and long-term survival curves of patients with CLTI. Systemic improvements in access to care will be needed to allow for broad application of these imaging assessments should they prove universally valuable. Additional study is required to determine the benefit of selective coronary revascularization in patients with CLTI., (© 2023 The Author(s).)

Objective: Endovascular repair of abdominal aortic aneurysm (AAA) remains a challenging clinical scenario when there is a short or nonexistent segment of healthy infrarenal aorta. This study sought to determine the safety and effectiveness of endosuture aneurysm repair (ESAR) using the Endurant II/IIs endograft (Medtronic Vascular, Santa Rosa, Calif) in conjunction with Heli-FX EndoAnchors (Medtronic Vascular) in the treatment of short-neck AAA., Methods: In this subgroup analysis, 70 patients were identified from the Aneurysm Treatment Using the Heli-FX EndoAnchor System Global Registry (ANCHOR) who had an infrarenal neck length <10 mm down to 4 mm based on core laboratory measurements. Primary outcomes included technical success of the index procedure, rate of type IA endoleak at 1 month and 12 months, and rate of secondary procedures at 12 months., Results: In this short-neck cohort (n = 70), the average neck length and diameter were 6.9 ± 1.6 mm and 25.7 ± 4.0 mm, respectively. Investigators reported an overall procedural success rate of 97.1% and a technical success rate of 88.6%. The duration of the implant procedure, EndoAnchor implantation, and total fluoroscopy time was 148.0 ± 80.0 minutes, 17.1 ± 11.5 minutes, and 35.3 ± 22.0 minutes, respectively, and an average of 5.5 ± 2.1 EndoAnchors were implanted per patient. Through the 30-day follow-up, type IA endoleaks were reported in four patients, of which three resolved spontaneously by the 12-month follow-up. There was an additional type IA endoleak through the 12-month follow-up that has not resulted in AAA enlargement or required a secondary procedure. The Kaplan-Meier estimate for freedom from secondary endovascular procedures and all-cause mortality is 95.4% and 92.7% through 365 days, respectively. No patient in the short-neck cohort experienced main body stent migration, increase in maximum aneurysm diameter, or aneurysm rupture or required conversion to open surgical repair through 12 months., Conclusions: In this analysis of the short-neck cohort from ANCHOR, the Endurant II/IIs endograft in conjunction with Heli-FX EndoAnchor implants (ESAR) appears to be a safe and effective treatment option with a high technical success rate and low incidence of type IA endoleaks and secondary interventions. Despite the complex and hostile anatomies, the ESAR method required short procedure and fluoroscopy times. These short-term outcomes suggest that ESAR could be complementary to therapies currently available for treatment of hostile AAA anatomy and a viable off-the-shelf endovascular treatment option for patients with short-neck AAAs, although long-term follow-up is critically important., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate clinical, anatomic, and procedural characteristics of patients who developed retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD)., Methods: Between January 2012 and January 2017, there were 186 patients who underwent TEVAR for TBAD at a multidisciplinary aortic center. Patients who developed RTAD after TEVAR (n = 15) were compared with those who did not (no-RTAD group, n = 171). Primary outcomes were survival and need for reintervention., Results: The incidence of RTAD in our sample was 8% (n = 15). Kaplan-Meier estimates found that no-RTAD patients had better survival (P = .04). Survival rates at 30 days, 1 year, and 3 years were 93%, 60%, and 60% for RTAD patients and 94%, 87%, and 80% for no-RTAD patients. One RTAD was diagnosed intraoperatively, 5 were diagnosed within 30 days of the index procedure, 6 were diagnosed within 1 year, and 3 were diagnosed after 1 year. Reintervention for RTAD was undertaken in 10 of 15 patients, with a 50% survival rate after reintervention. Partial or complete false lumen thrombosis was more frequently present in RTAD patients (P = .03). RTAD patients more frequently presented with renal ischemia (P = .04). Most RTAD patients (93%, RTAD patients; 64%, no-RTAD patients; P = .02) had a proximal landing zone in zone 0, 1, or 2. Aortic diameter was more frequently ≥40 mm in the RTAD group (47%, RTAD patients; 21%, no-RTAD patients; P = .05). Patients with RTAD had stent grafts placed in the renovisceral arteries for complicated dissections, and this approached significance (P = .05). Three RTAD patients had a type II arch (20%) compared with 53 no-RTAD patients (31%; P = .6), but a comparison of type II arch with type I or type III found no statistical significance (P = .6). No correlations were found between ratio of descending to ascending diameters, average aortic sizing, graft size, or bare-metal struts at proximal attachment zone and development of RTAD. We found no statistically significant differences in demographics, genetic disease, comorbidities, or previous repairs., Conclusions: The development of RTAD after TEVAR for TBAD does not appear to be correlated with any easily identifiable demographic feature but appears to be correlated with proximal landing zones in zone 1 and 2 and an ascending diameter >4 cm. Furthermore, the presence of partial or complete false lumen thrombosis as well as more complicated presentation with renal ischemia was significantly more frequent in patients with RTAD. TBAD patients should be observed long term, as type A dissections in our patients occurred even after 1 year., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

The complex aortic anatomy of patients who present with juxtarenal and pararenal abdominal aortic aneurysms requires advanced techniques to ensure adequate coverage and complete exclusion of the aneurysm. Parallel stent grafting is one option for endovascular repair of complex aneurysms. Using chimneys, periscopes, or snorkels, it is possible to extend the length of the proximal seal zone and maintain perfusion to branch vessels. Because readily available stent grafts and covered stents are used, this technique is highly adaptable to each patient's unique anatomical challenges. However, the complexity of these procedures requires careful preoperative planning, excellent intraoperative imaging capabilities, a thorough understanding of technique, and anticipation of potential procedural pitfalls and complications. We present our experience with chimney/snorkel and sandwich techniques as a reliable and effective treatment strategy for complex aortic aneurysm repair., (Copyright © 2018. Published by Elsevier Inc.)

The GORE TAG Thoracic Endoprosthesis (TAG) device (W. L. Gore & Associates, Flagstaff, Ariz) and the GORE Conformable TAG Thoracic Endoprosthesis (CTAG) are commonly implanted and effective stent grafts for use during thoracic endovascular aortic repair. Precise placement of the endograft is paramount during thoracic endovascular aortic repair, but like all thoracic stent grafts, maldeployment with inaccurate landing has been reported. The partial distal deployment technique describes an alteration of the TAG and CTAG deployment mechanism to allow isolated deployment of the distal half of the graft, which provides stability during deployment. The graft can be safely repositioned after partial distal deployment, thus allowing precise positioning in the proximal landing zone. Similarly, this technique can be used for precision in the distal landing zone, making the TAG and CTAG devices the only thoracic endografts currently available in the United States with a distal-first deployment option. A discussion of the usefulness of this technique and potential pitfalls is included., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Fenestrated endovascular aneurysm repair (FEVAR) is an alternative to open repair of complex aortic aneurysms. Despite promising short-term results, the technical complexities of this procedure remain a considerable challenge. The risk of technical failure with loss of visceral or renal arteries is ubiquitous even in the most experienced hands, and thus many patients with unfavorable anatomy are frequently denied FEVAR. We have adopted a new technique for FEVAR that involves retrograde brachial artery access and stepwise deployment of the endograft during target vessel catheterization, overcoming many anatomic limitations encountered from a transfemoral approach. This technique, termed sequential catheterization amid progressive endograft deployment, has become our preferred approach for FEVAR and is described in this article. Of note, currently available Food and Drug Administration-approved fenestrated endografts may not be amenable to sequential catheterization amid progressive endograft deployment as this technique requires preloaded wires incorporated into the endografts., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Purpose: To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success., Technique: The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements., Conclusion: With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization., (© The Author(s) 2016.)

Objectives: Mortality and complication rates for open thoracic aortic aneurysm repair have declined but remain high. The purpose of this study is to determine the influence of ethnicity and insurance type on procedure selection and outcome after open thoracic aneurysm repair., Methods: Using the Nationwide Inpatient Sample database, ethnicity and insurance type were evaluated against the outcome variables of mortality and major complications associated with open thoracic aneurysm repair. The potential cofounders of age, gender, urgency of operation, and Deyo index of comorbidities were controlled., Results: Between 2001 and 2005, a total of 10,557 patients were identified who underwent elective open thoracic aneurysm repair, with a significantly greater proportion of white patients (n = 8524) compared with black patients (n = 819), Hispanic patients (n = 556), and patients categorized as other (n = 658). Most patients (67%) were male. Almost half (45%) of the procedures were performed for urgent/emergent indications. Overall mortality was 10.7% (n = 1126) and the rate of spinal cord ischemia was 0.4% (n = 43). Univariate analysis revealed significant differences among race with regard to surgery type, income, hospital region, hospital bed size, and insurance type (P < 0.0001). Differences between insurance coverage were significant for gender, surgery type, income, hospital region, and race (P < 0.0001). Bivariate analysis by race revealed differences for death (P < 0.0001), pneumonia (P < 0.0001), renal complications (P = 0.011), implant complications (P < 0.0001), temporary tracheostomy (P = 0.004), transfusion (P < 0.0001), and intubation (P < 0.0001). In terms of payer status, bivariate analysis by insurance coverage revealed differences in death (P < 0.0001), central nervous system complications (P = 0.008), pneumonia (P < 0.0001), myocardial infarction (P = 0.001), infection (P < 0.0001), renal complications (P < 0.0001), malnutrition (P < 0.0001), temporary tracheostomy (P < 0.0001), spinal cord ischemia (P = 0.001), transfusion (P < 0.0001), and intubation (P < 0.0001)., Conclusions: A high percentage of open thoracic procedures (45%) are performed urgently or emergently in the United States, which is associated with increased morbidity and mortality. Both ethnicity and payer status were associated with significant differences in surgical outcomes, including mortality and frequency of complications after open thoracic aortic aneurysm repair., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Treatment of deep venous thrombosis (DVT) with therapeutic anticoagulation has been increasingly challenged by aggressive percutaneous treatment using ultrasound-accelerated catheter-directed thrombolysis (US-CDT) or percutaneous pharmacomechanical thrombectomy (PMT). These techniques have been promoted to improve thrombus removal, prolong venous patency, prevent venous insufficiency, and reduce postthrombotic syndrome. This study reviews midterm results using these endovascular techniques for both acute and chronic DVT., Methods: A retrospective chart review was performed on patients treated for acute or chronic DVT with US-CDT and/or PMT. Charts were reviewed for patient demographics, medical history and treatment, operative details, and postoperative outcomes. Intraoperative venography and intravascular ultrasound quantified clot response to therapy. Duplex ultrasound defined the pre- and postoperative extent of venous thrombosis, venous patency, and valvular function., Results: Between October 1, 2002 and September 30, 2010, 80 patients were treated for iliofemoral (n = 48), iliofemoropopliteal (n = 15), or femoropopliteal (n = 17) venous thrombosis. Mean age was 45.8 years (range, 15-78 years), and 24 patients (30%) had a documented history of hypercoagulable state. Intravascular ultrasound confirmed May-Thurner syndrome in 34 patients (42.5%). Fifty-two patients (65%) were treated for acute DVT; the mean time to intervention from symptom onset was 8.7 ± 4.5 days (range, 1-14 days). The remaining 28 patients (35%) had chronic symptoms and were treated at a mean of 8.6 ± 10.9 months (range, 1.5-36 months) after DVT diagnosis was made. Patients were treated with PMT (n = 43, 53.8%), US-CDT (n = 14, 17.5%), or both (n = 32, 28.7%). Clot lysis (>90%) was achieved in 72 of 80 patients (90%). Tenecteplase was used for all cases, and the mean dose was 8.6 ± 4.3 mg. Adjunctive procedures, including angioplasty with or without stent placement, were required in 90% (n = 47) of acute patients and in 96% (n = 27) of chronic patients (P = .33). Three patients (3.8%) had postoperative bleeding events requiring blood transfusion; there were no occurrences of intracranial hemorrhage or clinically significant pulmonary embolism. At a mean follow-up of 3.8 years (range, 1-8.9 years), venous patency was present in 49 of 52 acute patients (94%) and in 23 of 28 chronic patients (82%) (P = .12). Valve function was preserved in 41 of 52 (79%) acute patients vs 11 of 28 (39%) chronic patients (P < .001)., Conclusions: US-CDT and PMT can effectively remove acute and chronic thrombus in the lower extremity deep venous system. Vein patency and valvular function is better preserved at midterm follow-up after treatment for acute DVT, however intervention should be considered in patients with chronic DVT as well., (Copyright © 2013 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

We report the case of a 26-year-old female patient with Marfan syndrome and an aberrant right subclavian artery (ARSA) with associated Kommerell diverticulum. The patient presented with spontaneous acute dissection of the ARSA that showed fusiform dilation to 4 cm in diameter. Definitive treatment was performed using a two-stage hybrid endovascular technique, including extrathoracic bilateral upper extremity bypass and thoracic endovascular aortic repair with debranching of the right and left subclavian arteries. This was followed by coil and plug embolization to exclude the dissection and prevent subsequent endoleak., (Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The development of new wine yeast strains with improved characteristics is critical in the highly competitive wine market, which faces the demand of ever-changing consumer preferences. Although new strains can be constructed using recombinant DNA technologies, consumer concerns about genetically modified (GM) organisms strongly limit their use in food and beverage production. We have applied a non-GM approach, adaptive evolution with sulfite at alkaline pH as a selective agent, to create a stable yeast strain with enhanced glycerol production; a desirable characteristic for wine palate. A mutant isolated using this approach produced 41% more glycerol than the parental strain it was derived from, and had enhanced sulfite tolerance. Backcrossing to produce heterozygous diploids revealed that the high-glycerol phenotype is recessive, while tolerance to sulfite was partially dominant, and these traits, at least in part, segregated from each other. This work demonstrates the potential of adaptive evolution for development of novel non-GM yeast strains, and highlights the complexity of adaptive responses to sulfite selection.

Background: Conventional repair of aortic arch pathology is associated with significant mortality and stroke rates of 6-20% and 12%, respectively. Because endografting has excellent results for descending thoracic aortic disease, extension of thoracic endovascular repair (TEVAR) to the arch is a consideration., Methods: Records of patients with aortic arch pathology treated with TEVAR were reviewed. Branch vessels were (1) covered without revascularization, (2) surgically bypassed, (3) stented, or (4) fenestrated. Technical success was defined both by accurate endograft deployment with disease exclusion and by target vessel revascularization. Patient postoperative outcomes, complications, and follow-up are reported., Results: Between March 2006 and January 2010, 58 patients with arch pathology were treated with TEVAR. Indications included aneurysm (n = 19, 32.8%), dissection (type A: n = 3, 5.2%; type B: n = 18, 31.0%), transection (n = 8, 13.8%), pseudoaneurysm (n = 6, 10.3%), or other (n = 4, 6.9%). Pathology was zone 0 (n = 1, 1.7%), zone 1 (n = 10, 17.2%), zone 2 (n = 45, 77.6%), or zone 3 (n = 2, 3.4%). Interventions were emergent in 44.8% and elective in 55.2%. The left subclavian (LSA) was covered in all and revascularized (n = 23, 39.7%) via bypass (n = 13, 22.4%), stenting (n = 4, 6.9%), or fenestration (n = 6, 10.3%). The carotid was revascularized (n = 11, 19.0%) with bypass (n = 7, 12.1%) or stenting (n = 4, 6.9%). One patient (1.7%) underwent innominate revascularization with a homemade branched endograft. Technical success was 100% for endograft deployment and 97.1% for revascularization. Thirty-day mortality was 3.4% (2 of 58). ICU and hospital stays were 5.8 ± 6.8 (range: 0-34; median 4) and 10.9 ± 8.0 (range: 1-40; median: 9) days, respectively. Morbidities included renal failure (n = 3, 5.2%), respiratory (n = 2, 3.4%), myocardial infarction (n = 1, 1.7%), stroke (n = 6, 10.3%), and spinal cord ischemia (SCI) (n = 2, 3.4%). SCI (p < 0.001), but not stroke (p = 0.33), was associated with LSA sacrifice. Stroke was associated with underlying pathology and graft selection (p = 0.01). During follow-up of 10.6 ± 9.1 (range: 0-43) months, 17 patients (29.3%) required 20 reinterventions for endoleak (n = 8, 13.8%), disease extension (n = 5, 8.6%), steal (n = 4, 6.9%), or other reasons (n = 3, 5.2%). Dissection patients had a higher rate of reintervention (p = 0.01). All patients with steal had LSA sacrifice and were left-hand dominant., Conclusions: TEVAR can effectively treat aortic arch pathology in high-risk patients with low morbidity and mortality. TEVAR and branch vessel revascularization techniques may be extended to the more proximal arch without increased complications compared with patients with subclavian only involvement. Stroke remains the most significant drawback of arch interventions. Indications for intervention, graft selection, and revascularization choices may all affect outcome. LSA sacrifice is associated with increased SCI and may predispose left-handed patients to symptomatic weakness., (Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.)

Background: Type B aortic dissections are being successfully treated by thoracic endovascular aortic repair (TEVAR). Postoperative false lumen patency has been associated with aneurysmal dilatation and rupture of the thoracic aorta, necessitating further intervention. This is the first volumetric analysis of type B aortic dissections comparing patients with and without false lumen thrombosis (FLT) after TEVAR. We hypothesized that a greater increase in postoperative true lumen volume will lead to FLT, and without this change, false lumen patency will result., Methods: Preoperative and postoperative computed tomography angiography (CTA) imaging was analyzed using three-dimensional reconstruction to measure the short- and long-axis diameter and cross-sectional area of the true lumen, false lumen, and total aorta. Measurements were taken at 5-cm intervals from the left subclavian artery to the aortic bifurcation. Pre- and postoperative volumetric data were calculated and compared in patients with and without postoperative FLT., Results: Between 2006 and 2010, 132 patients underwent thoracic aortic stent grafting. Of these, 31 (23%) had thoracic endografting for type B aortic dissection. Pre- and postoperative CTA images were available for analysis in 23 patients with a mean age of 59 ± 14 years treated for acute, complicated (n = 8, 35%), and chronic (n = 15, 65%) indications. Mean follow-up imaging was 9 months (range, 1-39 months). Thirteen patients (56%) had postoperative FLT and 10 (43%) had persistent false lumen patency. The dissections involved the left subclavian artery (n = 12), visceral arteries (n = 14), renal arteries (n = 16), and iliac arteries (n = 15). The left subclavian artery was intentionally covered in 15 patients (65%). There were no significant differences in age, acute vs chronic dissection, branch vessel involvement, coverage of the left subclavian artery, or distal extent of the endograft between patients with and without postoperative FLT. Patients with postoperative FLT had a significantly smaller preoperative maximum thoracic aortic diameter (5.05 ± 1.0 vs 6.30 ± 1.4 cm; P = .02). Volumetric analysis demonstrated significantly smaller preoperative true lumen volume (141.3 ± 68 vs 230.5 ± 92 cm(3); P = .01) in patients with FLT, but no difference in preoperative false lumen volume. Patients with FLT had a significant increase in the volume percentage of the true lumen from 42.7% to 61.7% (P = .02) after stent graft repair, compared with an increase from 46.7% to 47.7% (P = .75) in patients with persistent false lumen patency., Conclusions: This volumetric study of type B aortic dissection treated with TEVAR suggests that the ability of the endograft to significantly increase the true lumen volume as a percent of the total aorta most accurately predicts postoperative FLT. This is best demonstrated in a nonaneurysmal dissection regardless of timing since dissection., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Purpose: To evaluate the effects of type II endoleaks and sac pressurization on stent-graft displacement following endovascular aneurysm repair (EVAR)., Methods: Experimental silicone infrarenal aneurysm (6-cm) models were "treated" with a Talent stent-graft deployed with 20-mm proximal and distal landing zones. Inflow and outflow vessels were created as part of the silicone model to control flow into the aneurysm sac. All aneurysm models were uniform, with a diameter neck of 31 mm, a neck length of 20 mm, and iliac artery diameters of 16 mm. The aortic model was secured in a water bath to a pulsatile pump under physiological conditions; the output phase ratio (%systole/%diastole) was set at 65/35 with a pump rate of 80 beats per minute. Commercially available bifurcated stent-grafts were then displaced in vitro utilizing a linear motion apparatus attached to a force gauge. The mean arterial pressure (MAP) and pulse pressure (PP) at the aortic inflow were 60.1 ± 3.1 and 38.3 ± 7.8 mmHg, respectively. Peak force to cause initial stent-graft migration with and without a type II endoleak was recorded and compared., Results: In aneurysm sacs with no endoleak, the MAP and sac PP were 32 ± 6.4 and 6 ± 1.3 mmHg, respectively (p<0.01). In aneurysm sacs with a type II endoleak, the MAP and sac PP were 54.1 ± 9.7 and 16.1 ± 4.1 mmHg, respectively (p<0.02). Peak force to initiate migration was 16.0 ± 1.41 N (range 15-18) with no endoleak vs. 23.2 ± 2.2 N (range 20-25) in those with a type IIa endoleak and 23.5 ± 2.5 N (range 20-26) in those with a type IIb endoleak (p<0.001)., Conclusion: Type II endoleaks are associated with a significantly increased sac pressure. Increased sac pressurization from type II endoleaks results in a significantly greater force to displace a stent-graft longitudinally. Type II endoleaks may therefore inhibit migration and offer a benefit following EVAR; however, clinical correlation of these results is required.

Saccharomyces spp. are widely used for ethanol production; however, fermentation productivity is negatively affected by the impact of ethanol accumulation on yeast metabolic rate and viability. This study used microarray and statistical two-way ANOVA analysis to compare and evaluate gene expression profiles of two previously generated ethanol-tolerant mutants, CM1 and SM1, with their parent, Saccharomyces cerevisiae W303-1A, in the presence and absence of ethanol stress. Although sharing the same parentage, the mutants were created differently: SM1 by adaptive evolution involving long-term exposure to ethanol stress and CM1 using chemical mutagenesis followed by adaptive evolution-based screening. Compared to the parent, differences in the expression levels of genes associated with a number of gene ontology categories in the mutants suggest that their improved ethanol stress response is a consequence of increased mitochondrial and NADH oxidation activities, stimulating glycolysis and other energy-yielding pathways. This leads to increased activity of energy-demanding processes associated with the production of proteins and plasma membrane components, which are necessary for acclimation to ethanol stress. It is suggested that a key function of the ethanol stress response is restoration of the NAD(+)/NADH redox balance, which increases glyceraldehyde-3-phosphate dehydrogenase activity, and higher glycolytic flux in the ethanol-stressed cell. Both mutants achieved this by a constitutive increase in carbon flux in the glycerol pathway as a means of increasing NADH oxidation.

There are five retrotransposon families in Saccharomyces cerevisiae, three (Ty1, Ty2, and Ty3) of which are known to be transcriptionally active. Early investigations reported yeast retrotransposons to be stress-induced; however, microarray-based studies do not report retrotransposition-related Gene Ontology (GO) categories in the ethanol stress response of S. cerevisiae. In this study, microarray technology was used to investigate the ethanol stress response of S. cerevisiae W303-1A, and the highest stress-induced GO categories, based on z-score, were found to be retrotransposition-related, namely, Retrotransposition Nucleocapsid and Transposition, RNA-Mediated. Further investigation, involving reanalysis of previously published results on the stress response of S. cerevisiae, identified the absence of annotation for retrotransposon genes and associated GO categories and their omission during the printing of spotted arrays as two reasons why these categories in previous gene expression studies on the ethanol stress response of yeast were not reported.

Saccharomyces cerevisiae is traditionally used for alcoholic beverage and bioethanol production; however, its performance during fermentation is compromised by the impact of ethanol accumulation on cell vitality. This article reviews studies into the molecular basis of the ethanol stress response and ethanol tolerance of S. cerevisiae; such knowledge can facilitate the development of genetic engineering strategies for improving cell performance during ethanol stress. Previous studies have used a variety of strains and conditions, which is problematic, because the impact of ethanol stress on gene expression is influenced by the environment. There is however some commonality in Gene Ontology categories affected by ethanol assault that suggests that the ethanol stress response of S. cerevisiae is compromised by constraints on energy production, leading to increased expression of genes associated with glycolysis and mitochondrial function, and decreased gene expression in energy-demanding growth-related processes. Studies using genome-wide screens suggest that the maintenance of vacuole function is important for ethanol tolerance, possibly because of the roles of this organelle in protein turnover and maintaining ion homoeostasis. Accumulation of Asr1 and Rat8 in the nucleus specifically during ethanol stress suggests S. cerevisiae has a specific response to ethanol stress although this supposition remains controversial., (© 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.)

Saccharomyces spp. are widely used for ethanologenic fermentations, however yeast metabolic rate and viability decrease as ethanol accumulates during fermentation, compromising ethanol yield. Improving ethanol tolerance in yeast should, therefore, reduce the impact of ethanol toxicity on fermentation performance. The purpose of the current work was to generate and characterise ethanol-tolerant yeast mutants by subjecting mutagenised and non-mutagenised populations of Saccharomyces cerevisiae W303-1A to adaptive evolution using ethanol stress as a selection pressure. Mutants CM1 (chemically mutagenised) and SM1 (spontaneous) had increased acclimation and growth rates when cultivated in sub-lethal ethanol concentrations, and their survivability in lethal ethanol concentrations was considerably improved compared with the parent strain. The mutants utilised glucose at a higher rate than the parent in the presence of ethanol and an initial glucose concentration of 20 g l(-1). At a glucose concentration of 100 g l(-1), SM1 had the highest glucose utilisation rate in the presence or absence of ethanol. The mutants produced substantially more glycerol than the parent and, although acetate was only detectable in ethanol-stressed cultures, both mutants produced more acetate than the parent. It is suggested that the increased ethanol tolerance of the mutants is due to their elevated glycerol production rates and the potential of this to increase the ratio of oxidised and reduced forms of nicotinamide adenine dinucleotide (NAD(+)/NADH) in an ethanol-compromised cell, stimulating glycolytic activity.

Trehalose is known to protect cells from various environmental assaults; however, its role in the ethanol tolerance of Saccharomyces cerevisiae remains controversial. Many previous studies report correlations between trehalose levels and ethanol tolerance across a variety of strains, yet variations in genetic background make it difficult to separate the impact of trehalose from other stress response factors. In the current study, investigations were conducted on the ethanol tolerance of S. cerevisiae BY4742 and BY4742 deletion strains, tsl1Delta and nth1Delta, across a range of ethanol concentrations. It was found that trehalose does play a role in ethanol tolerance at lethal ethanol concentrations, but not at sublethal ethanol concentrations; differences of 20-40% in the intracellular trehalose concentration did not provide any growth advantage for cells incubated in the presence of sublethal ethanol concentrations. It was speculated that the ethanol concentration-dependent nature of the trehalose effect supports a mechanism for trehalose in protecting cellular proteins from the damaging effects of ethanol.

In the simultaneous saccharification and fermentation to ethanol of 100 g l(-1) microcrystalline cellulose, the cellobiose-fermenting recombinant Klebsiella oxytoca P2 outperformed a range of cellobiose-fermenting yeasts used in earlier work, despite producing less ethanol than reported earlier for this organism under similar conditions. The time taken by K. oxytoca P2 to produce up to about 33 g l(-1) ethanol was much less than for any other organism investigated, including ethanol-tolerant strains of Saccharomyces pastorianus, Kluyveromyces marxianus and Zymomonas mobilis. Ultimately, it produced slightly less ethanol (maximum 36 g l(-1)) than these organisms, reflecting its lower ethanol tolerance. Significant advantages were obtained by co-culturing K. oxytoca P2 with S. pastorianus, K. marxianus or Z. mobilis, either isothermally, or in conjunction with temperature-profiling to raise the cellulase activity. Co-cultures produced significantly more ethanol, more rapidly, than either of the constituent strains in pure culture at the same inoculum density. K. oxytoca P2 dominated the early stages of the co-cultures, with ethanol production in the later stages due principally to the more ethanol tolerant strain. The usefulness of K. oxytoca P2 in cellulose simultaneous saccharification and fermentation should be improved by mutation of the strain to increase its ethanol tolerance.

Large inocula of Stenotrophomonas maltophilia VUN 10,003 were used to investigate bacterial degradation of benzo[a]pyrene and dibenz[a,h]anthracene. Although strain VUN 10,003 was capable of degrading 10-15 mg (-1) of the five-ring compounds in the presence of pyrene after 63 days, further addition of pyrene after degradation of the five-ring polycyclic aromatic hydrocarbons (PAHs) ceased did not stimulate significant decreases in the concentration of benzo[a]pyrene or dibenz[a,h]anthracene. However, pyrene was degraded to undetectable levels 21 days after its addition. The amount of benzo[a]pyrene and dibenz[a,h]anthracene degraded by strain VUN 10,003 was not affected by the initial concentration of the compounds when tested at 25-100 mg l(-1), by the accumulation of by-products from pyrene catabolism or a loss of ability by the cells to catabolise benzo[a]pyrene or dibenz[a,h]anthracene. Metabolite or by-product repression was suspected to be responsible for the inhibition: By-products from the degradation of the five-ring compounds inhibited their further degradation.

The ability of Stenotrophomonas maltophilia strain VUN 10,003 to degrade and detoxify high molecular weight polycyclic aromatic hydrocarbons (PAHs) was evaluated in a basal liquid medium. Using high cell density inocula of strain VUN 10,003, the concentration of pyrene, fluoranthene, benz[a]anthracene, benzo[a]pyrene, dibenz[a, h]anthracene and coronene decreased by 98, 45, 26, 22, 22 and 55% over periods ranging from 5 to 42 d. When a PAH mixture containing three- to seven-ring compounds was used, degradation of both low and high molecular weight compounds occurred concurrently. Mutagenicity assays (Ames Test) demonstrated a decrease in the mutagenic potential of dichloromethane culture extracts from all cultures containing single PAH over the incubation period, corresponding to the decrease in the concentration of the PAH. These observations indicate that strain VUN 10,003 could be used for the detoxification of PAH-contaminated wastes.

This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10, 201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO(2) by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization (53% of added [(14)C]benzo[a]pyrene was recovered as (14)CO(2) in 100 days), and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula.