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Contains fulltext : 81225.pdf (publisher's version ) (Closed access), BACKGROUND: In the chronic constriction injury model of rat neuropathic pain, oxidative stress as well as antioxidants superoxide dismutase and reduced glutathione (GSH) are important determinants of neuropathological and behavioral consequences. Studies of the chronic constriction injury model observed (indirect) signs of inflammation. We, therefore, investigated the level of oxidative stress and antioxidant enzymes in skeletal muscle tissue of the rat hind paw and (jugular vein) plasma at d 7 after nerve injury. MATERIALS AND METHODS: The level of reactive oxygen and nitrogen species (RONS) was determined as a measure of oxidative stress. Reduced GSH levels and the ceruloplasmin/transferrin ratio were determined as measures of overall antioxidant activity. RONS and overall antioxidant activity were measured in skeletal muscle tissue of the hind paw and jugular vein plasma. The level of RONS in muscle was determined using spin trapping combined with electron paramagnetic resonance spectroscopy. Using electron paramagnetic resonance spectroscopy, we also determined plasma levels of transferrin and ceruloplasmin. GSH levels were determined using high-performance liquid chromatography. RESULTS: In skeletal muscle tissue, the level of RONS was lower in nerve-injured hind paws than in controls. The plasma level (jugular vein) of RONS did not differ between nerve-injured and control rats. In skeletal muscle tissue, the level of GSH was higher in nerve-injured hind paws than in controls. The ceruloplasmin/transferrin ratio tended to be higher in (jugular vein) plasma of nerve-injured rats as compared to controls. CONCLUSIONS: This study shows that, at d 7 after nerve injury, oxidative stress-induced changes are present also in skeletal muscle tissue of the rat hind paw. Our findings of a decreased level of RONS in combination with an increased level of the antioxidant GSH suggest that an overshoot of antioxidant activity overrules initial oxidative stress.

Contains fulltext : 80256.pdf (publisher's version ) (Closed access), Preoperative positron emission tomography/computed tomography (PET/CT) was performed in 26 consecutive patients considered fit for aneurysm repair. Besides information on aneurysm wall pathology, PET/CT identified 6 patients with concomitant malignancy. As a result of this coincidental finding, the operation was postponed in 2 patients and cancelled in 1. Although previous studies have shown that PET/CT might affect patient selection based on aneurysm wall inflammation, our preliminary results show a big impact on patient management as a result of the sensitivity of PET/CT for detecting malignancy. Future larger studies are warranted to investigate the effect and cost effectiveness of routine PET/CT in abdominal aortic aneurysm (AAA) patients.

RU Radboud Universiteit Nijmegen, 04 juni 2009, Promotores : Blankensteijn, J.D., Schultze Kool, L.J., Oyen, W.J.G. Co-promotor : Kurvers, H.A.J.M., Contains fulltext : 74421.pdf (publisher's version ) (Open Access)

Contains fulltext : 80262.pdf (publisher's version ) (Open Access), PURPOSE: To evaluate in-vivo thrombus compressibility in abdominal aortic aneurysms (AAAs) to hopefully shed light on the biomechanical importance of intraluminal thrombus. METHODS: Dynamic electrocardiographically-gated computed tomographic angiography was performed in 17 AAA patients (15 men; mean age 73 years, range 69-76): 11 scheduled for surgical repair and 6 under routine surveillance. The volumes of intraluminal thrombus, the lumen, and the total aneurysm were quantified for each phase of the cardiac cycle. Thrombus compressibility was defined as the percent change in thrombus volume between diastole and peak systole. Continuous data are presented as medians and interquartile ranges (IQR). RESULTS: A substantial interpatient variability was observed in thrombus compressibility, ranging from 0.4% to 43.6% (0.2 to 13.5 mL, respectively). Both thrombus and lumen volumes varied substantially during the cardiac cycle. As lumen volume increased (5.2%, IQR 2.8%-8.8%), thrombus volume decreased (3.0%, IQR 1.0%-4.6%). Total aneurysm volume remained relatively constant (1.3%, IQR 0.4-1.9%). Changes in lumen volume were inversely correlated with changes in thrombus volume (r = -0.73; p = 0.001). CONCLUSION: In-vivo thrombus compressibility varied from patient to patient, and this variation was irrespective of aneurysm size, pulse pressure, and thrombus volume. This suggests that thrombus might act as a biomechanical buffer in some, while it has virtually no effect in others. Whether differences in thrombus compressibility alter the risk of rupture will be the focus of future research.

Contains fulltext : 69773.pdf (publisher's version ) (Closed access), PURPOSE: To study the potential of integrated positron emission tomography and computed tomography (PET/CT) to identify aneurysm wall inflammation. METHODS: The level of F18-fluorodeoxyglucose (FDG) uptake was studied in aneurysmal and normal-sized aortas of 34 male patients [17 with abdominal aortic aneurysm (AAA) and 17 age-matched controls] identified in a database of 278 consecutive patients evaluated for staging of primary lung cancer. The maximal standardized uptake value (SUV) was calculated to quantify FDG uptake in the AAA wall. RESULTS: AAAs showed significantly higher FDG uptake than the normal-sized aorta in age-matched controls (SUV 2.52+/-0.52 versus 1.78+/-0.45, respectively; p<0.001). The level of FDG uptake did not correlate with maximal aneurysm diameter (r=0.09; 95% CI -0.42 to 0.56; p=0.7). CONCLUSION: FDG-PET/CT is a promising technique to identify inflammation of the aneurysm wall. Irrespective of aneurysm diameter, asymptomatic AAAs show more FDG uptake and more inflammatory activity in the wall than the non-dilated abdominal aorta of sex/age-matched controls. Future studies will be directed at the predictive value of increased FDG uptake for aneurysm wall strength, rupture risk, and the utility of FDG-PET/CT in assessing the effect of medical interventions.