Aortic pulse wave velocity in subjects with aortic valve sclerosis

Background: Aortic stiffness is an independent risk factor for cardiovascular events and mortality. The measurement of pulse‐wave velocity (PWV) is the most simple, noninvasive, and robust method to determine aortic stiffness. Whether aortic stiffness contributes to aortic valve sclerosis (AVS) remains unknown. The aim of the present study was to examine the relationship between PWV and AVS in subjects free of clinically evident atherosclerotic disease. Methods: We enrolled 62 patients (48 men; age 65 ± 8 years) diagnosed with AVS and an additional 62 age‐, hypertension‐, diabetes mellitus‐, and history of smoking‐matched subjects without AVS. Applanation tonometry was applied to assess the augmentation index and aortic PWV. The subjects with symptomatic vascular disease were excluded from the study. AVS was defined by echocardiography as thickening and calcification of the normal trileaflet aortic valve without obstruction to the left ventricular outflow. Results: There was no significant difference between the two groups regarding the aortic PWV and augmentation index (11.7±3.3 vs 11.8±3.7, P=0.85; 28.0±9.4 vs 25.0±8.6, P=0. 17, respectively). The presence of AVS was significantly correlated with ejection fraction (r=0.211, P=0.011), male gender (r=0.362, P=0.0001), and age (r=0.200, P=0.026). Conclusions: The lack of an association between the aortic PWV and AVS suggests that AVS is a complex phenomenon consisting of several distinct processes, related to both atherosclerotic and nonatherosclerotic processes.     

Increased levels of soluble adhesion molecules E-selectin and P-selectin in patients with cardiac syndrome X

The role of endothelial dysfunction and platelet activation in patients with cardiac syndrome X is controversial. The aim of this study was to investigate the plasma levels of circulating E- and P-selectin molecules in patients with syndrome X. The study included 21 patients with cardiac syndrome X (11 men and 10 women, mean age = 56 +/- 5 years) and 20 patients with significant coronary artery disease who had stable angina pectoris (11 men and 9 women, mean age = 60 +/- 8 years). Twenty-two age- and sex-matched subjects (12 men and 10 women, mean age = 58 +/- 8 years) undergoing diagnosis of atypical chest pain in whom coronary arteries were found normal and exercise test had no signs of ischemia served as the control group. Syndrome X was defined as presence of typical chest pain on exertion or at rest with positive exercise test and angiographically normal epicardial coronary arteries with no evidence of coronary spasm after intracoronary infusion of ergonovine maleate. The mean plasma concentrations of P-selectin were significantly elevated both in patients with coronary artery disease and syndrome X as compared with control subjects (49.15 +/-7.47 and 42.80 +/- 8.93 vs 22.63 +/-6.47 ng/mL, p < 0.001). Similarly, both patients with coronary artery disease and syndrome X had higher plasma concentrations of E-selectin than the control group (78.85 +/- 16.69 and 68.38 +/- 15.30 vs 36.43 +/- 4.72 ng/mL, p < 0.001). In conclusion, patients with syndrome X had increased plasma concentrations of soluble adhesion molecules, E-selectin and P-selectin, reflecting an ongoing chronic inflammation involved with endothelial dysfunction and enhanced platelet activation/damage in this setting.     

The Springer Model for Lifetime Prediction of Wind Turbine Blade Leading Edge Protection Systems: A Review and Sensitivity Study

The wind energy sector is growing rapidly. Wind turbines are increasing in size, leading to higher tip velocities. The leading edges of the blades interact with rain droplets, causing erosion damage over time. In order to mitigate the erosion, coating materials are required to protect the blades. To predict the fatigue lifetime of coated substrates, the Springer model is often used. The current work summarizes the research performed using this model in the wind energy sector and studies the sensitivity of the model to its input parameters. It is shown that the Springer model highly depends on the Poisson ratio, the strength values of the coating and the empirically fitted a2 constant. The assumptions made in the Springer model are not physically representative, and we reasoned that more modern methods are required to accurately predict coating lifetimes. The proposed framework is split into three parts—(1) a contact pressure model, (2) a coating stress model and (3) a fatigue strength model—which overall is sufficient to capture the underlying physics during rain erosion of wind turbine blades. Possible improvements to each of the individual aspects of the framework are proposed.     

Pleural fluid neopterin levels in tuberculous pleurisy

OBJECTIVES: Neopterin is produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It is regarded as a biochemical marker of cell-mediated immune response. This study was designed to assess the diagnostic value of pleural fluid neopterin levels in tuberculous pleurisy in comparison with adenosine deaminase activity. DESIGN AND METHODS: Pleural fluid adenosine deaminase (ADA) activity and neopterin levels were measured in 16 patients with tuberculous pleurisy (TP) and 19 patients with malignant pleurisy (MP). ADA activity was determined by a colorimetric method, whereas neopterin levels were determined by a reversed-phase liquid chromatography technique. All values were given as median (min-max). RESULTS: The mean age was 45.43+/-20.39 years in the TP group and 60.42+/-11.02 years in the MP group (p=0.026). The median pleural fluid ADA activity was 51.75 U/L (3.50-62.40 U/L) in the TP group and was 2.30 U/L (1-8.20 U/L) in the MP group. The difference was statistically significant (p<0.001). The median pleural fluid neopterin levels were 13.15 nmol/L (1.86-59.50 nmol/L) and 2.44 nmol/L (0.92-27.60 nmol/L) in the TP group and the MP group, respectively (p=0.021). In order to evaluate the diagnostic value of pleural fluid neopterin concentrations, receiver-operating-characteristic curve analysis was performed. CONCLUSION: Pleural fluid neopterin concentration is significantly higher in TP when compared to MP, however when compared, its clinical use as a diagnostic marker is not valuable as ADA.     

Acute vitreomacular traction syndrome after uneventful phacoemulsification

We prospectively evaluated 59 eyes following uneventful phacoemulsification and intraocular lens implantation with optic coherence tomography at one and seven postoperative days (POD). Acute vitreomacular traction was observed in two eyes (3.3%) at the first POD. Spontaneous resolution occurred in both eyes within one week. The temporary visual loss associated with acute vitreomacular traction syndrome may go unnoticed as visual acuity rapidly improves.     

Bilateral massive choroidal hemorrhage secondary to Glanzmann's syndrome

Characteristics of intraocular bleeding and its management in association with blood dyscrasias are discussed. We present a patient with massive bilateral choroidal hemorrhage secondary to Glanzmann's syndrome. Magnetic resonance imaging and ultrasonographic findings were ordered. During the clinical course, bilateral intravitreal hemorrhage and tractional retinal detachment occurred. Left pars plana vitrectomy was performed under general anaesthesia. The procedure was unsuccessful because of intraoperative uncontrolled bleeding.     

Management of carotid artery invasion in advanced malignancies of head and neck comparison of techniques

The objective of this study was to retrospectively investigate a single institution's experience with carotid artery resection performed as part of an oncological procedure and to determine acute and convalescent complication and survival rates. We performed a record review of 28 patients with head and neck malignancy invading the carotid artery. Immediate carotid artery resection and ligation on an emergent basis was performed on 12 patients (group 1), elective resection and ligation was performed on 8 patients (group 2), and elective resection and revascularization was performed on 8 patients (group 3). In group 1, although 1 patient survived for 1 year and 1 patient survived for 2 years, 1 patient died of severe neurologic deficit, 2 patients experienced neurologic deficit with good recovery, and 1 patient was moderately disabled. In group 2, 2 patients survived without disease for 5 years, and 2 patients experienced neurologic deficit, 1 with good recovery and the other with complete recovery. In group 3, only 1 patient survived for 5 years, and within this group, 1 patient died of severe neurologic deficit, 1 patient had neurologic deficit with moderate recovery, and 1 patient had neurologic deficit with complete recovery. No significant difference in mortality and morbidity rate was observed between the "resection and ligation" group and the "resection and revascularization" group (p = .52, chi(2) = 0.79). We conclude that the surgical treatment of patients with an invaded carotid artery, including carotid resection, provides a small but real chance of 5-year survival. The methods of carotid resection and repair should be guided by clinical presentation and by preoperative and intraoperative investigations.     

Incidence of cochlear involvement in hyperbilirubinemic deafness

Neonatal hyperbilirubinemia remains an important cause of childhood deafness, especially in developing countries. After neonatal hyperbilirubinemia, the auditory neural pathways, cochlea, or both may be affected. In this study, we aimed to determine the incidence of cochlear impairment and the appropriate means of hearing screening in hyperbilirubinemic neonates. A retrospective review of 1,032 pediatric patients with hearing loss revealed 67 cases (6.5%) of severe hyperbilirubinemia in the neonatal period. Thirty of these patients had neonatal hyperbilirubinemia as the single identifiable risk factor for hearing loss. In 26 of 30 cases (87%), otoacoustic emissions (OAEs) were absent, whereas in the remaining 4 cases (13%), robust emissions were detected despite an absent auditory brain stem response (ABR). Auditory screening of newborns with jaundice by OAEs possesses a significant risk of undiagnosed deafness. On the other hand, if the ABR is used as the single means of screening, auditory neuropathic conditions will probably be underlooked. Therefore, we recommend dual screening of hearing by ABR and OAEs in hyperbilirubinemic newborns.     

The organochlorine pesticide residues and antioxidant enzyme activities in human breast tumors: is there any association?

The levels of some organochlorine pesticides (OCP)s (hexachlorobenzene, HCB, -hexachlorocyclohexane, -HCH, -HCH, -HCH, heptachlorepoxide, HE, bis (4-chlorophenyl)-1,1-dichloroethene, p.pDDE, bis (4-chlorophenyl)-1,1,1-trichloroethane, p.p DDT and total DDT (-DDT) and antioxidant enzyme activities namely Cu, Zn superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px), total glutathione peroxidase (T-GSH-Px), selenium independent glutathione peroxidase (GSH-Px II), glutathione reductase (GRd), level of reduced glutathione (GSH) and lipid peroxidation (LP), glutathione S-transferase (GST) activity toward several substrates including 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (ENPP) were measured in tumor and surrounding tumor free tissues of 24 female breast cancer patients and was evaluated whether there exist any association between the levels of OCPs and antioxidants. The mean levels of GSH, -BHC, -BHC and HE, and activities of SOD, Se-GSH-Px, T-GSH-Px, GSH-Px II,GRd, GST CDNB, and GST DCNB were significantly higher in tumors than in controls. In tumors, significant correlations were noted between: SOD and -BHC; Se-GSH-Px and -BHC; T-GSH-Px and -BHC; GSH-Px II and -BHC, -BHC; GSH and -BHC, -BHC, HE; GRd and -BHC; CDNB GST and -BHC, -BHC. These results show that free-radical mediated oxidative stress is, at least partly, associated with some of these OCP residues in human breast tumors.