http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Tue, 16 Apr 2013 18:28:07 +0000 http://www.hindawi.com/journals/phj/2013/598321/ One response to hypertonic stress in the renal medulla and MDCK cells is the upregulation of betaine transporter (BGT1) synthesis, followed by trafficking to the plasma membrane (PM) and an increase in betaine transport. Upregulation of BGT1 was enhanced by inhibitors of phosphatases PP1 and PP2A and was attenuated by inhibitors of protein kinase C, suggesting an important role for phosphorylation reactions. This was tested using mutants of BGT1 tagged with EGFP. The PM trafficking motifs of BGT1 reside near the C terminus, and truncation at lysine560 resulted in a protein that remained intracellular during hypertonic stress. This K560 mutant colocalized with endoplasmic reticulum (ER). Substitution of alanine at Thr40, a putative phosphorylation site, also prevented trafficking to the PM during hypertonic stress. Live-cell imaging showed that T40A was not retained in the ER and colocalized with markers for Golgi and endosomes. In contrast, substitution of aspartate or glutamate at Thr40, to mimic phosphorylation, restored normal trafficking to the PM. HEK293 cells transfected with K560 or T40A mutants had 10% of the GABA transport activity of native BGT1, but normal transport activity was restored in cells expressing T40E. Normal BGT1 trafficking likely requires phosphorylation at Thr40 in addition to C-terminal motifs. Christopher R. Day, Sashana S. Gordon, Cherissa L. Vaughn, and Stephen A. Kempson Copyright © 2013 Christopher R. Day et al. All rights reserved. Sun, 07 Apr 2013 14:39:18 +0000 http://www.hindawi.com/journals/phj/2013/584717/ The human myometrium is mainly relaxed during pregnancy, but, up to term, contractions become more coordinated and forceful in order to initiate delivery. Small conductance Ca2+-activated K+ channels (SK channels) in human myometrium have been shown to be downregulated in late pregnancy. The aim was to investigate the presence of SK2 and SK3 in the human myometrium from nonpregnant women, pregnant women at term, and pregnancies delivered preterm and, in addition, to characterize the time of downregulation of these channels. Using qRT-PCR, we observed significantly lower levels of mRNA for SK2 than for SK3 in the nonpregnant tissue. The mRNA levels of SK3 were significantly reduced in tissue from pregnancies at term and pregnancies resulting in preterm deliveries, whereas no downregulation for SK2 was observed. Western blotting confirmed the qRT-PCR results. Using immunohistochemical staining, both SK2 and SK3 were detected in endometrial glandular epithelium. We conclude that SK3 mRNA is downregulated early in pregnancy—at least among those that result in preterm deliveries. Furthermore, we find that SK channels are expressed not only in the uterine smooth muscle but also in the endometrial epithelium. M. Rahbek, S. T. Rosenbaum, M. J. Dahl, D. A. Klaerke, L. Ødum, S. S. Poulsen, T. Larsen, and P. Bouchelouche Copyright © 2013 M. Rahbek et al. All rights reserved. Wed, 06 Mar 2013 15:12:36 +0000 http://www.hindawi.com/journals/phj/2013/517838/ The study aimed to assess by an electromyographic (EMG), mechanomyographic (MMG), and force-combined approach the electrochemical and mechanical components of the overall electromechanical delay during relaxation (R-EMD). Reliability of the measurements was also assessed. To this purpose, supramaximal tetanic stimulations (50 Hz) were delivered to the gastrocnemius medialis muscle of 17 participants. During stimulations, the EMG, MMG, and force signals were detected, and the time lag between EMG cessation and the beginning of force decay ( EMG-F, as temporal indicators of the electrochemical events) and from the initial force decrease to the largest negative peak of MMG signal during relaxation ( F-MMG, as temporal indicators of the mechanical events) was calculated, together with overall R-EMD duration (from EMG cessation to the largest MMG negative peak during relaxation). Peak force (pF), half relaxation time (HRT), and MMG peak-to-peak during the relaxation phase (R-MMG p-p) were also calculated. Test-retest reliability was assessed by Intraclass Correlation Coefficient (ICC). With a total R-EMD duration of 96.9 ± 1.9 ms, EMG-F contributed for about 24% (23.4 ± 2.7 ms) while F-MMG for about 76% (73.5 ± 3.2 ms). Reliability of the measurements was high for all variables. Our findings show that the main contributor to R-EMD is represented by the mechanical components (series elastic components and muscle fibres behaviour), with a high reliability level for this type of approach. Emiliano Cè, Susanna Rampichini, Eloisa Limonta, and Fabio Esposito Copyright © 2013 Emiliano Cè et al. All rights reserved. Tue, 26 Feb 2013 15:28:04 +0000 http://www.hindawi.com/journals/phj/2013/254789/ A novel noninvasive technique was applied to measure velocity within slow conducting axons in the distal extreme of the sciatic nerve (i.e., digital nerve) in a rat model. The technique is based on the extraction of rectified multiple unit activity (MUA) from in vivo whole nerve compound responses. This method reliably identifies compound action potentials in thinly myelinated fibers conducting at a range of 9–18 m/s ( axons), as well as in a subgroup of unmyelinated C fibers conducting at approximately 1-2 m/s. The sensitivity of the method to C-fiber conduction was confirmed by the progressive decrement of the responses in the 1-2 m/s range over a 20-day period following the topical application of capsaicin (ANOVA ). Increasing the frequency of applied repetitive stimulation over a range of 0.75 Hz to 6.0 Hz produced slowing of conduction and a significant decrease in the magnitude of the compound C-fiber response (ANOVA ). This technique offers a unique opportunity for the noninvasive, repeatable, and quantitative assessment of velocity in the subsets of and C fibers in parallel with the evaluation of fast nerve conduction. Elena G. Zotova and Joseph C. Arezzo Copyright © 2013 Elena G. Zotova and Joseph C. Arezzo. All rights reserved. Thu, 21 Feb 2013 14:20:42 +0000 http://www.hindawi.com/journals/phj/2013/154327/ Remote ischemic preconditioning (IPC) is a procedure during which brief periods of ischemia protect distant organ from ischemia-reperfusion injury. Appling IPC on an upper arm, this phenomenon has been demonstrated in several studies. Skeletal muscle tissue oxygenation at rest (StO2) and StO2 deoxygenation rate during vascular occlusion can be measured using near infrared spectroscopy (NIRS). We aimed to investigate the effects of remote upper arm IPC on StO2 and flow-mediated dilatation (FMD) in healthy male volunteers. In a randomized controlled crossover trial, resting StO2, StO2 deoxygenation rate, and FMD were measured on testing arm at baseline and after 60 minutes. After basal measurements IPC protocol on a contralateral arm was performed. StO2 deoxygenation rate was significantly lower after remote, the IPC cycles in comparison to deoxygenation rate at baseline ( versus %, ). Comparison of deoxygenation rates showed a significant difference between the IPC and the control protocol (, ). No differences were observed in FMD before and after remote IPC and in the control protocol. In healthy young adults, remote IPC reduces StO2 deoxygenation rate but has no significant impact on FMD. NIRS technique offers a novel approach to asses skeletal muscle adaptation in response to remote ischemic stimuli. Jana Ambrozic, Mitja Lainscak, and Matej Podbregar Copyright © 2013 Jana Ambrozic et al. All rights reserved. Tue, 29 Jan 2013 14:25:10 +0000 http://www.hindawi.com/journals/phj/2013/539076/ The first aim of the study is to determine whether combined lung diffusing capacities of nitric oxide (TLNO) and of carbon monoxide (TLCO) are accurate in the followup of patients receiving either methotrexate (MTX) or bleomycin (BLM). The second objective is to determine whether TLCO, TLNO, KCO, and TLCO/VI% (inspiratory volume expressed as percentage of predicted value) correlate better with the diffusing capacity of the membrane (Dm) and/or capillary lung volume (Vc). TLNO and TLCO were measured in three groups: 22 “normal” subjects (N group), 17 patients receiving MTX, and 12 patients treated with BLM. TLCO, TLNO, Dm, and Vc were much lower in the MTX and BLM groups compared to those of the N one. The ratio TLNO/TLCO was higher in the BLM group compared to that of the N group and compared to that of the MTX group. KCO correlated neither with Dc nor with Vc, whereas TLCO/VI% correlated significantly with both Dm and Vc. Combined measurement of TLCO and TLNO seems to be useful in the followup of patients receiving agents inducing lung toxicity and gives a good idea of the alveolar membrane and the capillary volume. Chantal Viart-Ferber, Sébastien Couraud, Frédéric Gormand, and Yves Pacheco Copyright © 2013 Chantal Viart-Ferber et al. All rights reserved. Mon, 14 Jan 2013 08:19:42 +0000 http://www.hindawi.com/journals/phj/2013/847325/ This study measured cognitive and vascular responses to aerobic training in sedentary young adults. Ten adults (6 women, 4 men; 18–29 years) were randomly assigned to an experimental or no-treatment control group. The experimental group engaged in a 6-week intervention, performed on exercise cycle and treadmill, 3x/week, 50 min/session; intensity was increased over time. Outcome measures included arterial stiffness (augmentation index, AIx, and pulse pressure), cardiorespiratory fitness (), and cognitive function (attention, processing speed, working memory, episodic memory, and executive function). Participants randomized to aerobic training improved processing speed versus control (, ES = 0.55). However, no group × time effects were noted in other domains of cognitive function. AIx was reduced by approximately 16% from before to after intervention in the experimental group; however, the improvement was not statistically significant versus control (, ES = 0.22). Pulse pressure did not change between groups over time (, ES = 0.0). increased by approximately 10% in the experimental group; however, the change was not significant between groups over time (, ES = 0.27). Vascular and cognitive adaptations to aerobic training may move in parallel. Robust trials simultaneously investigating a broad spectrum of aerobic training interventions and vascular and cognitive outcomes are warranted. Samuel Asamoah, Jason Siegler, Dennis Chang, Andrew Scholey, Alan Yeung, and Birinder S. Cheema Copyright © 2013 Samuel Asamoah et al. All rights reserved.