12 research outputs found
Combined Endovascular/Surgical Management of a Ruptured Para-Anastomotic Aneurysm of the Left Common Iliac Artery#
A 75-year old man presented with signs and symptoms of acute abdomen and a clinical picture of hypovolemic shock. An emergency CT scan revealed a ruptured para-anastomotic left common iliac artery aneurysm. The patient had undergone an elective abdominal aortic aneurysm repair operation and placement of an aortoiliac bifurcated graft 10 years before. Para-anastomotic aneurysms had developed in all 3 (aortic and the 2 iliac) anastomosis. As the patient was highrisk, a combined endovascular/surgical approach was undertaken. The patient was discharged 4 days later
Evaluation of Aortic Stiffness (Aortic Pulse–Wave Velocity) Before and After Elective Abdominal Aortic Aneurysm Repair Procedures: A Pilot Study#
New Cerebral Ischemic Lesions After Carotid Endarterectomy
Background: We sought to investigate the incidence and location of new
cerebral ischemic lesions after carotid endarterectomy (CEA) using
diffusion-weighted magnetic resonance imaging (DW-MRI).
Methods: Sixty-six consecutive patients (50 males with a mean [+/- SD]
age of 69 +/- 9 years) who underwent CEA were included in this
prospective study. Seventeen patients were symptomatic and 49 patients
were asymptomatic. CEA was performed with patch closure without using a
shunt. Carotid plaque echostructure was evaluated with the grayscale
median (GSM) score. DW-MRI scanning of the brain was performed 24 hours
before and 48 to 72 hours after the procedure.
Results: Thirty-day stroke and mortality rates were 0%. The mean GSM
score for symptomatic patients was 27 +/- 15; for asymptomatic patients,
the mean GSM score was 39 +/- 18 (P = 0.006). Patients were divided into
2 groups according to GSM score: GSM scores <= 25 (22 patients) and GSM
scores >26 (44 patients). New brain lesions were detected after 6
endarterectomies (8.9%), and all were clinically silent. These lesions
were ischemic in 5 cases (7.5%) and micro-hemorrhagic in 1 case
(1.4%). In 3 cases, new ischemic lesions were located within the
treated carotid artery territory. In 2 cases, new lesions on DW-MRI were
located outside of the treated carotid artery territory. There was no
significant difference in the incidence of ischemic lesions between the
2 groups (GSM scores <= 25, 2 lesions; GSM scores >26, 3 lesions; P =
0.544).
Conclusions: New ischemic lesions on DW-MRI are detected in 7.5% of
patients after CEA, and most of these lesions are clinically silent.
Plaque echogenicity does not affect their incidence. New lesions seen on
DW-MRI may be generated outside of the treated carotid artery territory
High Catalytic Efficiency of a Nanosized Copper-Based Catalyst for Automotives: A Physicochemical Characterization
The global trend in restrictions on pollutant emissions requires the use of catalytic converters in the automotive industry. Noble metals belonging to the platinum group metals (PGMs, platinum, palladium, and rhodium) are currently used for autocatalysts. However, recent efforts focus on the development of new catalytic converters that combine high activity and reduced cost, attracting the interest of the automotive industry. Among them, the partial substitution of PGMs by abundant non-PGMs (transition metals such as copper) seems to be a promising alternative. The PROMETHEUS catalyst (PROM100) is a polymetallic nanosized copper-based catalyst for automotives prepared by a wet impregnation method, using as a carrier an inorganic mixed oxide (CeO2-ZrO2) exhibiting elevated oxygen storage capacity. On the other hand, catalyst deactivation or ageing is defined as the process in which the structure and state of the catalyst change, leading to the loss of the catalyst’s active sites with a subsequent decrease in the catalyst’s performance, significantly affecting the emissions of the catalyst. The main scope of this research is to investigate in detail the effect of ageing on this low-cost, effective catalyst. To that end, a detailed characterization has been performed with a train of methods, such as SEM, Raman, XRD, XRF, BET and XPS, to both ceria–zirconia mixed inorganic oxide support (CZ-fresh and -aged) and to the copper-based catalyst (PROM100-fresh and -aged), revealing the impact of ageing on catalytic efficiency. It was found that ageing affects the Ce–Zr mixed oxide structure by initiating the formation of distinct ZrO2 and CeO2 structures monitored by Raman and XRD. In addition, it crucially affects the morphology of the sample by reducing the surface area by a factor of nearly two orders of magnitude and increasing particle size as indicated by BET and SEM due to sintering. Finally, the Pd concentration was found to be considerably reduced from the material’s surface as suggested by XPS data. The above-mentioned alterations observed after ageing increased the light-off temperatures by more than 175 °C, compared to the fresh sample, without affecting the overall efficiency of the catalyst for CO and CH4 oxidation reactions. Metal particle and CeZr carrier sintering, washcoat loss as well as partial metal encapsulation by Cu and/or CeZrO4 are identified as the main causes for the deactivation after hydrothermal ageing
Serum Leptin Levels in Patients Undergoing Carotid Endarterectomy: A Pilot Study
Introduction: Elevated serum leptin levels are associated with
cardiovascular events. We investigated the role of serum leptin in
patients undergoing carotid endarterectomy (CEA). Methods: A total of 74
patients (55 men; 38 symptomatic and 36 asymptomatic; mean age 66.9 +/-
8.2 years) undergoing CEA for >70% carotid artery stenosis were
enrolled. Results: Serum leptin levels were lower in symptomatic
compared with asymptomatic patients (7.1 +/- 1.3 vs 14.4 +/- 4.7 ng/dL;
P < .001). Interleukin-6 (IL-6) levels were higher in symptomatic
compared with asymptomatic patients (4.3 +/- 1.7 vs 3.3 +/- 1.1 pg/dL; P
= .017). Symptomatic patients had more intense macrophage accumulation
(0.7% +/- 0.1% vs 0.3% +/- 0.1%; P < .001). Serum leptin and serum
IL-6 levels were independently associated with the presence of symptoms
in multivariate analysis. Conclusion: Serum leptin levels were decreased
in symptomatic carotid artery disease. This finding requires further
investigation in larger studies