Effect of ß-blocker on aneurysm sac behavior after endovascular abdominal aortic repair.

OBJECTIVE: This study was conducted to determine whether ß-blocker (BB) therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular abdominal aortic repair (EVAR). METHODS: A total of 198 patients (mean age, 76 years) who underwent EVAR were analyzed (104 in the BB group and 94 in the non-BB group). The primary end point was the incidence of AAA sac regression at 1 and 2 years. RESULTS: Hypertension, coronary artery disease, and hyperlipidemia were more common in the BB group. The BB group was also more likely to have been prescribed an aspirin and a statin than the non-BB group. The length of proximal neck was significantly longer in the non-BB group than in the BB group. All study patients were monitored for at least 1 year after EVAR, and 2-year follow-up was available in 104 patients (52.5%). There was no statistically significant difference in the incidence of aneurysm sac regression in either group at 1 year (52.1% in the non-BB group vs 45.2% in the BB group; P = .330) and 2 years (58.5% in the non-BB group vs 64.7% in the BB group; P = .515). The difference of the change of AAA maximum diameter between two groups did not reach statistical significance at 1 year (-6.0 ± 7.0 mm in the non-BB group vs -5.5 ± 8.1 mm in the BB group; P = .644) and 2 years (-9.0 ± 10.5 mm in the non-BB group vs -9.0 ± 10.0 mm in the BB group; P = .977). BB therapy was not associated with increased odds of AAA sac regression. The effect of third-generation BBs on AAA sac regression was not significant. CONCLUSIONS: BB therapy had no effect on AAA sac regression. At the present time, there is insufficient evidence to recommend BB therapy for the purpose of AAA sac regression.

Influence of Statin Therapy on Aneurysm Sac Regression after Endovascular Aortic Repair.

PURPOSE: To determine whether statin therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: A total of 109 patients treated with EVAR were retrospectively analyzed (no-statin group, n = 45; statin group, n = 64). The primary endpoint was the incidence of AAA sac regression. To investigate independent predictors of AAA sac regression, regression analysis was performed. The mean age was 74 years (range, 55-90 y), and 87.2% of patients were men. RESULTS: The no-statin group had higher rates of AAA sac regression than the statin group at 1 year (no-statin group, 66.7%; statin group, 45.3%; P = .028). The incidence of AAA sac regression increased over time in the statin group, and no statistical difference was seen between the two groups at 2 years (no-statin group, 66.7%; statin group, 57.8%; P = .350). The difference between the changes in maximum AAA diameter was significant between groups at 1 year (no-statin group vs statin group, -4.9 mm ± 5.9; P = .041), but the difference did not reach statistical significance at 2 years (no-statin group, -10.0 mm ± 10.1; statin group, -8.0 mm ± 9.6; P = .306). Statin therapy was not associated with AAA sac regression on univariate (odds ratio [OR], 0.685; 95% confidence interval [CI], 0.310-1.516; P = .351) and multivariate analyses (OR, 0.617; 95% CI, 0.215-1.772; P = .369). CONCLUSIONS: Statin therapy had no effect on AAA sac regression at 2 years. There is insufficient evidence to recommend statin therapy for AAA sac regression.

The Influence of Statin Therapy on Restenosis in Patients Who Underwent Nitinol Stent Implantation for de Novo Femoropopliteal Artery Disease: Two-Year Follow-up at a Single Center.

PURPOSE: To determine whether statin therapy is associated with reduced restenosis following nitinol stent implantation for de novo femoropopliteal artery disease. MATERIALS AND METHODS: A total of 135 limbs in 135 patients (mean age, 72 y) implanted with nitinol stents in femoropopliteal occlusions were analyzed (statin arm, n = 91; nonstatin arm, n = 44). The patients were treated with one type of nitinol stent. RESULTS: At baseline, lesions and procedural characteristics were comparable between groups, except that the statin group had more hypertension, coronary artery disease, and hyperlipidemia. There were significant differences in the incidence of binary restenosis between groups at 1 year (45.5% for nonstatin group vs 28.6% for statin group; P = .05) and 2 years (56.8% for nonstatin group vs 38.5% for statin group; P = .04). Primary patency rates at 1 year were 50.5% in the nonstatin group and 72.5% in the statin group (P = .01). Two-year target lesion revascularization rates were 54.5% in the nonstatin group and 35.2% in the statin group (P = .03). On univariate analysis, statin therapy was associated with decreased relative risk of binary restenosis at 1 year (odds ratio [OR], 0.480; 95% confidence interval [CI], 0.227-1.014; P = .050). On multivariate analysis, statin therapy did not significantly affect the odds of binary restenosis (OR, 0.415; 95% CI, 0.071-2.437; P = .330). CONCLUSIONS: The incidence of binary restenosis was significantly lower in the statin group than in the nonstatin group following nitinol stent implantation for de novo femoropopliteal artery disease.

Alkaline-Tolerant Bacillus cereus 12GS: A Promising Polyhydroxybutyrate (PHB) Producer Isolated from the North of Mexico.

Environmental pollution caused by petroleum-derived plastics continues to increase annually. Consequently, current research is interested in the search for eco-friendly bacterial polymers. The importance of Bacillus bacteria as producers of polyhydroxyalkanoates (PHAs) has been recognized because of their physiological and genetic qualities. In this study, twenty strains of Bacillus genus PHA producers were isolated. Production was initially evaluated qualitatively to screen the strains, and subsequently, the strain B12 or Bacillus sp. 12GS, with the highest production, was selected through liquid fermentation. Biochemical and molecular identification revealed it as a novel isolate of Bacillus cereus. Production optimization was carried out using the Taguchi methodology, determining the optimal parameters as 30 °C, pH 8, 150 rpm, and 4% inoculum, resulting in 87% and 1.91 g/L of polyhydroxybutyrate (PHB). Kinetic studies demonstrated a higher production within 48 h. The produced biopolymer was analyzed using Fourier-transform infrared spectroscopy (FTIR), confirming the production of short-chain-length (scl) polyhydroxyalkanoate, named PHB, and differential scanning calorimetry (DSC) analysis revealed thermal properties, making it a promising material for various applications. The novel B. cereus isolate exhibited a high %PHB, emphasizing the importance of bioprospecting, study, and characterization for strains with biotechnological potential.

Valve Endothelial Cell Exposure to High Levels of Flow Oscillations Exacerbates Valve Interstitial Cell Calcification.

The aortic valve facilitates unidirectional blood flow to the systemic circulation between the left cardiac ventricle and the aorta. The valve's biomechanical function relies on thin leaflets to adequately open and close over the cardiac cycle. A monolayer of valve endothelial cells (VECs) resides on the outer surface of the aortic valve leaflet. Deeper within the leaflet are sublayers of valve interstitial cells (VICs). Valve tissue remodeling involves paracrine signaling between VECs and VICs. Aortic valve calcification can result from abnormal paracrine communication between these two cell types. VECs are known to respond to hemodynamic stimuli, and, specifically, flow abnormalities can induce VEC dysfunction. This dysfunction can subsequently change the phenotype of VICs, leading to aortic valve calcification. However, the relation between VEC-exposed flow oscillations under pulsatile flow to the progression of aortic valve calcification by VICs remains unknown. In this study, we quantified the level of flow oscillations that VECs were exposed to under dynamic culture and then immersed VICs in VEC-conditioned media. We found that VIC-induced calcification was augmented under maximum flow oscillations, wherein the flow was fully forward for half the cardiac cycle period and fully reversed for the other half. We were able to computationally correlate this finding to specific regions of the aortic valve that experience relatively high flow oscillations and that have been shown to be associated with severe calcified deposits. These findings establish a basis for future investigations on engineering calcified human valve tissues and its potential for therapeutic discovery of aortic valve calcification.

Draft Genome Sequence of a Polyhydroxyalkanoate-Producing Bacillus cereus Strain Isolated from Nuevo Leon State, Mexico.

Polyhydroxyalkanoates (PHA) are microbially produced biopolymers which are biodegradable and biocompatible. These compounds produced by microorganisms have been described as a potent alternative to synthetic plastics, which are often recalcitrant. Here, we report the draft genome sequence of a PHA-producing Bacillus cereus isolated in our laboratory.

Utilization of Agave durangensis leaves by Bacillus cereus 4N for polyhydroxybutyrate (PHB) biosynthesis.

Lignocellulosic wastes may provide a means to economize polyhydroxybutyrate (PHB) production. This study has proposed the use of Agave durangensis leaves obtained from the artisanal mezcal industry as a novel substrate for this aim. Results revealed an increase in PHB biosynthesis (0.32 g/L) and improvement in %PHB (16.79-19.51%) by Bacillus cereus 4N when A. durangensis leaves used as carbon source were physically pre-treated by ultrasound for 30 min (ADL + US30') and thermally pre-treated (ADL + Q). Chemical analyses and SEM studies revealed compositional and morphological changes when A. durangensis leaves were physically pre-treated. Also, elemental analysis of growth media showed that carbon/nitrogen ratios of 14-21, and low nitrogen, hydrogen, and protein content were well-suited for PHB biosynthesis. Confocal microscopy revealed morphological changes in the bacterial cell and carbonosome structure under the influence of different substrates. Finally, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analyses showed that homopolymeric PHB with a high thermal-resistance (271.94-272.89 °C) was produced. Therefore, the present study demonstrates the potential use of physically pre-treated A. durangensis leaves to produce PHB. These results promote the development of a circular economy in Mexico, where lignocellulosic wastes can be employed to produce value-added biotechnological products.

Efficient recovery of thermostable polyhydroxybutyrate (PHB) by a rapid and solvent-free extraction protocol assisted by ultrasound.

Nowadays, there are great research interest in polyhydroxybutyrate (PHB) recovery protocols that reduce the use of organic solvents and efficiently recover this bacterial biopolymer. The present study reports an extraction protocol assisted by ultrasound, which is a rapid protocol that increases the amount of polymeric matter extracted, reduces the cellular digestion step with sodium hypochlorite and eliminates the use of organic solvents. Likewise, characterization studies by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) demonstrated that the biopolymer recovered by this protocol is PHB homopolymer with a major thermal-resistance and crystalline properties. Besides, in this study are reported the thermic and crystalline differences between the PHB obtained from the fermentation of complex carbohydrates (agavins) and simple sugars. The biopolymer obtained by this rapid extraction protocol would be suitable for ecological and biomedical applications, due to the low melting temperature, less than 50% crystallinity, and the lack of lipopolysaccharides. Therefore, this extraction protocol might represent an alternative to the traditional protocol based on NaOCl-chloroform and is part of the green trend to improve the PHB production.

Transapical endovascular repair of iatrogenic type A aortic dissection.

Intraoperative iatrogenic type A aortic dissection is a rare but known complication of cardiac surgery, with an incidence of 0.06% to 0.23%. Results are frequently catastrophic. The endovascular approach has made advances as an alternative treatment for aortic disease. However, the apical approach for transcatheter thoracic endovascular aortic repair is not well known. We present a 5-year follow-up of a case of iatrogenic type A aortic dissection after minimally invasive mitral valve repair successfully resolved by medical stabilization and subsequent transapical thoracic endovascular aortic repair.

Effects of Percutaneous Transluminal Angioplasty on Diastolic Function in Patients With Chronic Occlusion of Lower-Extremity Artery.

OBJECTIVE: We investigated whether successful revascularization of total occlusion of a large lower-extremity artery is associated with improvement of left ventricular (LV) diastolic function. BACKGROUND: Total occlusion of a large lower-extremity artery might affect the systemic vascular resistance and increase the afterload, because the left ventricle must work harder to eject blood into a smaller vascular bed. Chronic elevation of afterload is a cause of LV diastolic dysfunction. METHODS: This is a single-center retrospective analysis of 20 patients (10 men, age 69.6 ± 12.3 years) with chronic total occlusions (CTOs) of the aorto-iliac and femoropopliteal segments who underwent a successful endovascular revascularization. Baseline and postprocedural evaluation of diastolic function was performed, and the primary endpoint was improvement in LV diastolic function, which was defined as any decrease of the baseline E/E' ratio or any increase of the baseline E' velocity after the index procedure. RESULTS: There was a significant effect of successful revascularization on the E/A ratio (from 1.5 ± 1.1 to 1.0 ± 0.3; P=.046) because of a significant increase of A velocity (from 86.3 ± 30.4 cm/s to 98.3 ± 21.8 cm/s; P=.03). The E' velocity (from 7.4 ± 2.0 cm/s to 8.3 ± 2.3 cm/s; P=.07) did not show a significant increase, but there was a significant reduction in E/E' ratio (from 14.6 ± 3.9 to 12.4 ± 3.3; P=.02). Logistic regression analysis did not identify possible predictors of improvement in LV diastolic function. CONCLUSION: Our results showed that a successful revascularization was associated with improvement in the echocardiographic parameters of LV diastolic function in patients with CTO of large lower-extremity artery, and these changes may be related to the afterload reduction.