Continuous electroencephalographic monitoring and selective shunting reduces neurologic morbidity rates in carotid endarterectomy

Purpose:The role of continuous electroencephalographic (EEG) monitoring during carotid endarterectomy was evaluated in this retrospective review.Methods:We analyzed data from 902 consecutive carotid endarterectomy procedures performed with vein patch angioplasty. In 591 operations from 1980 to 1988 we did not use intraoperative EEG monitoring or shunting (non-EEG group). Continuous intraoperative EEG monitoring and selective shunting were used in 311 procedures from 1988 to 1994 (EEG group). The patients' mean age was higher in the EEG group (68.8 years; range, 41 to 87 years) than in the non-EEG group (66.2 years; range, 34 to 90 years; p < 0.001). There was also a significantly higher incidence of hypertension (56.2% vs 41.9%) and redo operations (5.4% vs 2.54%) in the EEG group than in the non-EEG group (p < 0.05). The operative technique was identical in both groups. We defined a significant EEG change as a greater than 50% reduction of the amplitude of the faster frequencies, a persistent increase of delta activity, or both.Results:In the EEG group, acute EEG changes occurred in 40 patients (12.8%); 31 (77.5%) unilateral and ipsilateral to the operated carotid artery, and nine (22.5%) bilateral. In five patients (12.5%) the changes correlated with an intraoperative episode of hypotension, and after normal blood pressure was restored the EEG returned to normal. In 35 procedures (87.5%) a carotid shunt was inserted. In 33 of those patients the EEG returned to baseline, in one patient there was a significant improvement, and in one patient the EEG changes persisted. Postoperative hospital strokes occurred in one patient (0.32%) in the EEG group and in 13 patients (2.19%) in the non-EEG group (p < 0.05). All strokes (n = 14) were ipsilateral to the operated carotid artery. Of the 13 strokes in the non-EEG group nine were major and four were minor. The one stroke in the EEG group was embolic in origin and occurred before carotid cross-clamping; it was associated with profound EEG changes that did not reverse after placement of a shunt. In the total group (n = 902), intraoperative EEG monitoring was inversely associated with postoperative stroke (p < 0.05).Conclusion:The overall neurologic morbidity rate was significantly lower in the EEG group than in the non-EEG group, thereby demonstrating the value of intraoperative EEG monitoring in carotid endarterectomy

Effectiveness of Non-nucleoside Reverse-Transcriptase Inhibitor-Based Antiretroviral Therapy in Women Previously Exposed to a Single Intrapartum Dose of Nevirapine: A Multi-country, Prospective Cohort Study

In a comparative cohort study, Jeffrey Stringer and colleagues investigate the risk of ART failure in women who received single-dose nevirapine for PMTCT, and assess the duration of increased risk

Intrinsically Tuning the Electromechanical Properties of Elastomeric Dielectrics:A Chemistry Perspective

Dielectric elastomers have the capability to be used as transducers for actuation and energy harvesting applications due to their excellent combination of large strain capability (100–400%), rapid response (10−3 s), high energy density (10–150 kJ m−3), low noise, and lightweight nature. However, the dielectric properties of non‐polar elastomers such as dielectric permittivity ε r , breakdown strength E b , and dielectric loss ε ″, need to be enhanced for real world applications. The introduction of polar groups or structures into dielectric elastomers through covalently bonding is an attractive approach to ‘intrinsically’ induce a permanent polarity to the elastomers, and can eliminate the poor post‐processing issues and breakdown strength of extrinsically modified materials, which have often been prepared by incorporation of fillers. This review discusses the chemical methods for modification of dielectric elastomers, such as hydrosilylation, thiol‐ene click chemistry, azide click chemistry, and atom transfer radical polymerization. The effects of the type and concentration of polar groups on the dielectric and mechanical properties of the elastomers and their performance in actuation and harvesting systems are discussed. State‐of‐the‐art developments and perspectives of modified dielectric elastomers for deformable energy generators and transducers are provided

The application of a commercially available citrus-based extract mitigates moderate NaCl-stress in arabidopsis thaliana plants

CITATION: Loubser, J. & Hills, P. 2020. The application of a commercially available citrus-based extract mitigates moderate NaCl-stress in arabidopsis thaliana plants. Plants, 9(8):1-23, doi:10.3390/plants9081010.The original publication is available at http://www.mdpi.comPublication of this article was funded by the Stellenbosch University Open Access FundAims: The aim of this study was to assess the effect of BC204 as a plant biostimulant on Arabidopsis thaliana plants under normal and NaCl-stressed conditions. Methods: For this study, ex vitro and in vitro growth experiments were conducted to assess the effect of both NaCl and BC204 on basic physiological parameters such as biomass, chlorophyll, proline, malondialdehyde, stomatal conductivity, Fv/Fm and the expression of four NaCl-responsive genes. Results: This study provides preliminary evidence that BC204 mitigates salt stress in Arabidopsis thaliana. BC204 treatment increased chlorophyll content, fresh and dry weights, whilst reducing proline, anthocyanin and malondialdehyde content in the presence of 10 dS·m−1 electroconductivity (EC) salt stress. Stomatal conductivity was also reduced by BC204 and NaCl in source leaves. In addition, BC204 had a significant effect on the expression of salinity-related genes, stimulating the expression of salinity-related genes RD29A and SOS1 independently of NaCl-stress. Conclusions: BC204 stimulated plant growth under normal growth conditions by increasing above-ground shoot tissue and root and shoot growth in vitro. BC204 also increased chlorophyll content while reducing stomatal conductivity. BC204 furthermore mitigated moderate to severe salt stress (10–20 dS·m−1) in A. thaliana. Under salt stress conditions, BC204 reduced the levels of proline, anthocyanin and malondialdehyde. The exact mechanism by which this occurs is unknown, but the results in this study suggest that BC204 may act as a priming agent, stimulating the expression of genes such as SOS1 and RD29A.https://www.mdpi.com/2223-7747/9/8/1010#citePublisher's versio

15. Measurement of esophageal temperature at two separate sites during pulmonary vein ablation

Pulmonary vein ablation (PVA) has been used to treat persistent supraventricular arrhythmias, in which a cardiologist first isolates and then thermally ablates the source of the arrhythmia1. Since the esophagus is in close proximity to the left atrium, heat induced injury to the esophagus may occur2. Although the incidence is low, the mortality rate is high. Luminal esophageal temperature (ET) monitoring is one of the most effective measures to minimize the risk of injury3. In this retrospective study, we elected to analyze temperature changes during PVA at two different temperature monitoring sites in the esophagus. Methods: The anesthetic technique was standardized and utilized general anesthesia, endotracheal intubation and an arterial line. ET monitors were placed at two mid-atrial locations, ET1 and ET2 separated by 1–1.5 inches in the esophagus, as determined by cardiologist using fluoroscopy. Temperatures at both ET1 and ET2 locations were recorded simultaneously when radio-frequency ablation was performed at different left atrial sites. The peak ET was recorded at each location. In particular, the increase over baseline ET and the difference between ET1 and ET2, were noted. Results: Twenty five patients were studied. Ablation sites in the left atrium included the anterior, posterior, inferior regions and the pulmonary veins. The most significant increases in temperature were seen during ablation of the posterior left atrium ranging from 0.1 to 4.0 degrees. However, in 20 out of 25 patients, measurements of ET1 ≠ ET2. The absolute value of difference of temperature between ET1 and ET2 ranged from 0.4 to 3.8, with a mean of 1.3 and a standard deviation of 1.1. Discussion: These findings suggest that measurement of temperature at two separate esophageal locations is more sensitive that one location in detecting temperature increases during PVA. The ablating electrode during PVA moves from different areas within the left atrium, and therefore, a wide area of temperature measurement is needed for more accurate monitoring. Furthermore, the most significant increases in temperature occurred when ablation performed in the posterior left atrium, adjacent to the esophagus. The implications of these observations suggest that one location of temperature measurement may not be accurate enough in detecting a “true” esophageal temperature. Further studies are needed to verify these findings in a prospective study and to ascertain whether this has any patient safety ramifications for preventing esophageal injury