The impact of remote ischemic preconditioning on cardiac biomarker and functional response to endurance exercise

Remote ischemic preconditioning (RIPC; repeated short reversible periods of ischemia) protects the heart against subsequent ischemic injury. We explored whether RIPC can attenuate post-exercise changes in cardiac troponin T (cTnT) and cardiac function in healthy individuals. In a randomized, crossover design, 14 participants completed 1-h cycling time trials (TT) on two separate visits; preceded by RIPC (arms/legs, 4 × 5-min 220 mmHg), or SHAM-RIPC (20 mmHg). Venous blood was sampled before and 0-, 1-, and 3-h post-exercise to assess high sensitivity (hs-)cTnT and brain natriuretic peptide (NT-proBNP). Echocardiograms were performed at the same time points to assess left and right ventricular systolic (ejection fraction; EF and right ventricular fractional area change; RVFAC, respectively) and diastolic (early transmitral flow velocities; E) function. Baseline hs-cTnT was not different between RIPC and SHAM. Post-exercise hs-cTnT levels were consistently lower following RIPC (18 ± 3 vs 21 ± 3; 19 ± 3 vs 23 ± 3; and 20 ± 2 vs 25 ± 2 ng/L at 0, 1 and 3-h post-exercise, respectively; P < 0.05). There was no main effect of time, trial, or interaction for NT-proBNP and left ventricular EF or RVFAC (all P < 0.05). A main effect of time was evident for E which transiently declined immediately after exercise to a similar level in both trials (0.85 ± 0.04 vs 0.74 ± 0.04 m/s, respectively; P < 0.05). In summary, RIPC was associated with lower hs-cTnT levels after exercise but there was no independent effect of RIPC for NT-proBNP or LV systolic and diastolic function. The lower hs-cTnT levels after RIPC suggests that further research should evaluate the role of ischemia in exercise-induced elevation in hs-cTnT.

Lateral weight transference exercises following acute stroke: a preliminary study of clinical effectiveness

Objectives: To evaluate a training programme aimed at improving lateral weight transference in patients following acute stroke to determine main treatment effects, if any, to inform the design of future studies.

Design: A single-blind randomized controlled trial.

Setting: The Stroke Unit at The James Cook University Hospital, Middlesbrough, UK.

Subjects: Thirty-five patients with an acute stroke.

Interventions: All subjects received their usual care, including physiotherapy. The treatment group (n / 17) received 12 additional therapy sessions (over four weeks) comprising exercises aimed at improving lateral weight transference in sitting delivered by trained physiotherapy assistants.

Main outcome measures: Measures of dynamic reaching, sitting and standing, and static standing balance were undertaken by a blind independent observer.

Results: Specific measures of weight displacement in standing and reaching, and timed standing up and sitting down did not detect any differences over time regardless of group. Neither were there any significant changes over time, except for sway during static standing (p B=0.01) and time to return to their original position during dynamic reaching (p / 0.01).

Conclusions: A training programme aimed at improving lateral weight transference did not appear to enhance the rehabilitation of acute stroke patients. Improvements observed in postural control in standing and sitting may be attributable to usual care or natural recovery.

Repeated Warm Water Immersion Induces Similar Cerebrovascular Adaptations to 8 Weeks of Moderate-Intensity Exercise Training in Females

Exercise training has the potential to enhance cerebrovascular function. Warm water immersion has recently been shown to enhance vascular function including the cerebrovascular response to heating. We suggest that passive heating can be used alternatively to exercise. Our aim was to compare the effects of exercise with warm-water immersion training on cerebrovascular and thermoregulatory function. 18 females (25±5 y) performed 8 weeks of cycling (70% HRmax) or warm water immersion (42°C) for 30 min 3 times per week. Brachial artery flow-mediated dilation (FMD) and peak cardiorespiratory fitness (VO2peak) were measured prior to and following both interventions. A passive heat stress was employed to obtain temperature thresholds (Tb) and sensitivities for sweat rate (SR) and cutaneous vasodilation (CVC). Middle cerebral artery velocity (MCAv) was measured throughout. FMD and VO2peak improved following both interventions (p<0.05). MCAv and cerebrovascular conductance were higher at rest and during passive heating (p<0.001 and <0.001, respectively) following both interventions. SR occurred at a lower Tb following both interventions and SR sensitivity also increased, with a larger increase at the chest (p<0.001) following water immersion. CVC occurred at a lower Tb (p<0.001) following both interventions. Warm water immersion elicits similar cerebrovascular, conduit, and thermoregulatory adaptations compared to a period of moderate-intensity exercise training.

The mechanisms of detoxification of As(III), dimethylarsinic acid (DMA) and As(V) in the microalga Chlorella vulgaris

The response of Chlorella vulgaris when challenged by As(III), As(V) and dimethylarsinic acid (DMA) was assessed through experiments on adsorption, efflux and speciation of arsenic (reduction, oxidation, methylation and chelation with glutathione/phytochelatin [GSH/PC]). Our study indicates that at high concentrations of phosphate (1.62mM of HPO4(2-)), upon exposure to As(V), cells are able to shift towards methylation of As(V) rather than PC formation. Treatment with As(V) caused a moderate decrease in intracellular pH and a strong increase in the concentration of free thiols (GSH). Passive surface adsorption was found to be negligible for living cells exposed to DMA and As(V). However, adsorption of As(III) was observed to be an active process in C. vulgaris, because it did not show saturation at any of the exposure periods. Chelation of As(III) with GS/PC and to a lesser extent hGS/hPC is a major detoxification mechanism employed by C. vulgaris cells when exposed to As(III). The increase of bound As-GS/PC complexes was found to be strongly related to an increase in concentration of As(III) in media. C. vulgaris cells did not produce any As-GS/PC complex when exposed to As(V). This may indicate that a reduction step is needed for As(V) complexation with GSH/PC. C. vulgaris cells formed DMAS(V)-GS upon exposure to DMA independent of the exposure period. As(III) triggers the formation of arsenic complexes with PC and homophytochelatins (hPC) and their compartmentalisation to vacuoles. A conceptual model was devised to explain the mechanisms involving ABCC1/2 transport. The potential of C. vulgaris to bio-remediate arsenic from water appeared to be highly selective and effective without the potential hazard of reducing As(V) to As(III), which is more toxic to humans.

The influence of visitor interaction on the behavior of captive crowned lemurs (Eulemur coronatus) and implications for welfare

Research suggests that zoo visitors can have positive, negative, and neutral impacts on captive primate welfare; however, research investigating the implications of visitor-animal feeding experiences is extremely limited. In the UK, a large proportion of BIAZA zoos that house lemur species offer visitor interaction experiences (16 out of 33). This study investigated the impact on the behavior of a family group of crowned lemurs (Eulemur coronatus) housed at Newquay Zoo, UK of visitors, accompanied by a keeper, entering the enclosure to feed the lemurs. Behavior was observed under four conditions: (i) during visitor feed; (ii) 30 min post-visitor feed; (iii) during a keeper feed; and (iv) 30 min post-keeper feed. Keeper feeds were conducted by keepers only, on the day after visitor feeds. The lemur group spent significantly less time performing aggressive behavior and was also significantly more interactive with keepers during visitor feeds compared with keeper-only feeds. There was no significant difference in behaviors performed immediately after interacting with visitors. Over the study period, there was a tendency for interactions with visitors to increase, and for interactions with keepers during visitor feeds to decrease. After a 28-day interval without visitor interaction, the lemurs' interaction with visitors had returned to the level recorded at the start of the study. In conclusion, visitor interaction did not compromise the welfare of the study subjects in either the short- or long-term, while an increase in visitor interactions over time has interesting implications for the enrichment properties of, or habituation to, unfamiliar humans. Zoo Biol. 35:222-227, 2016. © 2016 Wiley Periodicals, Inc.

IFPA meeting 2015 workshop report III: nanomedicine applications and exosome biology, xenobiotics and endocrine disruptors and pregnancy, and lipid

Workshops are an important part of the IFPA annual meeting, as they allow for discussion of specialized topics. At the IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops were related to various aspects of placental biology but collectively covered areas of pregnancy pathologies and placental metabolism: 1) nanomedicine applications and exosome biology; 2) xenobiotics and endocrine disruptors and pregnancy; 3) lipid mediators and placental function.