Protein oxidative damage in a transgenic mouse model of familial amyotrophic lateral sclerosis

The Gly93-->Ala mutation in the Cu,Zn superoxide dismutase (Cu,Zn-SOD) gene (SOD1) found in some familial amyotrophic lateral sclerosis (FALS) patients has been shown to result in an aberrant increase in hydroxyl radical production by the mutant enzyme that may cause oxidative injury to spinal motor neurons. In the present study, we analyzed the extent of oxidative injury to lumbar and cervical spinal cord proteins in transgenic FALS mice that overexpress the SOD1 mutation [TgN(SOD1-G93A)G1H] in comparison with nontransgenic mice. Total protein oxidation was examined by spectrophotometric measurement of tissue protein carbonyl content by the dinitrophenylhydrazine (DNPH) assay. Four ages were investigated: 30 (pre-motor neuron pathology and clinical disease), 60 (after initiation of pathology, but pre-disease), 100 (approximately 50% loss of motor neurons and function), and 120 (near complete hindlimb paralysis) days. Protein carbonyl content in 30-day-old TgN(SOD1-G93A)G1H mice was twice as high as the level found in age-matched nontransgenic mice. However, at 60 and 100 days of age, the levels were the same. Then, between 100 and 120 days of age, the levels in the TgN(SOD1-G93A)G1H mice increased dramatically (557%) compared with either the nontransgenic mice or transgenic animals that overexpress the wild-type human Cu,Zn-SOD [TgN(SOD1)N29]. The 100-120-day increase in spinal cord protein carbonyl levels was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoretic separation and western blot immunoassay, which enabled the identification of heavily oxidized individual proteins using a monoclonal antibody against DNPH-derivatized proteins. One of the more heavily oxidized protein bands (14 kDa) was identified by immunoprecipitation as largely Cu,Zn-SOD. Western blot comparison of the extent of Cu,Zn-SOD protein carbonylation revealed that the level in spinal cord samples from 120-day-old TgN(SOD1-G93A)G1H mice was significantly higher than that found in age-matched nontransgenic or TgN(SOD1)N29 mice. These results suggest that the increased hydroxyl radical production associated with the G93A SOD1 mutation and/or lipid peroxidation-derived radical species (peroxyl or alkoxyl) causes extensive protein oxidative injury and that the Cu,Zn-SOD itself is a key target, which may compromise its antioxidant function.     

The Influence of Therapist Adherence and Competence on Client Reprocessing of Child Abuse Memories.

This study follows previous research examining change processes in emotion-focused therapy for adult survivors of child abuse (N = 37). Therapist (n = 10) adherence to intervention principles and competence with an imaginal confrontation (IC) intervention were examined in the context of relationship skills. The Therapist Facilitating Scale assessed competence with IC. Therapists differed in technical (but not relationship) skills; relationship skills and IC competence (but not adherence) improved over therapy. Therapist competence predicted better client processes during IC. Relationship skills independently contributed to abuse resolution; the potency of IC (Competence x Frequency of Implementation) independently contributed to reduced interpersonal problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Motivating Impact of Informing Women Smokers of a Link Between Smoking and Cervical Cancer: The Role of Coherence.

This research assessed the role of having a coherent explanation of the link between smoking and cervical cancer in motivating women to stop smoking. In the 1st study, women were given a leaflet with either a detailed or a minimal explanation of the link or no leaflet. The leaflets were similarly effective at providing a coherent explanation. In a cross-sectional analysis, having a coherent explanation moderated the relationship between perceived vulnerability and intention: Higher perceived vulnerability to cervical cancer was associated with greater intention to quit smoking only amongst women with a more coherent explanation of the link between smoking and cervical cancer. This rinding was replicated in a 2nd study. These results are consistent with H. Leventhal et al.'s (1997) self-regulatory model, which suggests that motivation to change behavior depends not only on perceiving a threat but also on having a coherent model linking the behavior with the threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of tocopherols as antioxidants in ABS

Mixed tocopherols, γ‐tocopherol, and δ‐tocopherol were evaluated for antioxidant performance in acrylonitrile–butadiene–styrene by using oxidative induction time as the response. Three commonly used phenolic antioxidants and vitamin E (α‐tocopherol) were used as controls. Mixed tocopherols were found to have a greater antioxidant effect than the hindered phenolic antioxidants or vitamin E in acrylonitrile–butadiene–styrene. γ‐tocopherol was found to be primarily responsible for the improved performance of mixed tocopherols. J. VINYL. ADDIT. TECHNOL. 12:66–72, 2006. © 2006 Society of Plastics Engineers     

Hand–arm vibration in a group of hand‐operated grinding tools

Vibration acceleration was triaxially and basicentrically measured, and digital‐audio‐tape‐recorded with each axis separately evaluated using both the ANSI S3.34 and ACGIH hand‐arm vibration (HAV) guidelines, for two pairs of pneumatic handheld grinders commonly used in metal fabrication operations including shipyards. Each tool pair consisted of a new and used grinder of the same model, performing the same simulated grinding tasks using new small grinding wheels, carbide burrs, wire brushes, and flap wheels. The results of this limited study showed, primarily, that the HAV standards were not exceeded, but there was a consistent tendency for the acceleration levels to increase between new and used tools, ranging from 11% to 66% on the Z‐axis, 13% to 66% on the Y‐axis, 44% to 58% on the X‐axis, when tasks involved using grinding wheels and carbide burrs (hard implements). The results were mixed when using disposable wire brushes and flap wheels (softer implements). The overall results suggest the need for and implementation of a regular tool vibration monitoring and maintenance program as a primary element to help maintain tool acceleration levels to a minimum. © 2002 Wiley Periodicals, Inc.     

Minimising heat dissipation in ultrasonic piezomotors by working in a resonant mode

Heat dissipation in ultrasonic motors should be limited, especially in precision applications since it causes thermal deformations. Therefore, an easy-to-understand mechanical model was developed to simulate heat dissipation in an ultrasonic motor. This model involves the dielectric, piezoelectric and mechanical hysteretic losses of the piezoelectric material. Both the model and the experiments lead to the same recommendations to minimise the heat dissipation for ultrasonic motors. Large piezoactuators, exciting passive structures at high resonance frequencies result in a minimum heat dissipation. Furthermore, it was shown that the optimal frequency regarding minimal heat dissipation lies between the resonance and the antiresonance frequency of the system, close to the resonance frequency.