Efficacy of different 8 h time-restricted eating schedules on visceral adipose tissue and cardiometabolic health: A study protocol.

BACKGROUND AND AIMS: To investigate the efficacy and feasibility of three different 8 h time-restricted eating (TRE) schedules (i.e., early, late, and self-selected) compared to each other and to a usual-care (UC) intervention on visceral adipose tissue (VAT) and cardiometabolic health in men and women. METHODS AND RESULTS: Anticipated 208 adults (50% women) aged 30-60 years, with overweight/obesity (25 ≤ BMI<40 kg/m2) and with mild metabolic impairments will be recruited for this parallel-group, multicenter randomized controlled trial. Participants will be randomly allocated (1:1:1:1) to one of four groups for 12 weeks: UC, early TRE, late TRE or self-selected TRE. The UC group will maintain their habitual eating window and receive, as well as the TRE groups, healthy lifestyle education for weight management. The early TRE group will start eating not later than 10:00, and the late TRE group not before 13:00. The self-selected TRE group will select an 8 h eating window before the intervention and maintain it over the intervention. The primary outcome is changes in VAT, whereas secondary outcomes include body composition and cardiometabolic risk factors. CONCLUSION: This study will determine whether the timing of the eating window during TRE impacts its efficacy on VAT, body composition and cardiometabolic risk factors and provide insights about its feasibility.

Association of meal timing with body composition and cardiometabolic risk factors in young adults.

PURPOSE: To investigate the association of meal timing with body composition and cardiometabolic risk factors in young adults. METHODS: In this cross-sectional study participated 118 young adults (82 women; 22 ± 2 years old; BMI: 25.1 ± 4.6 kg/m2). Meal timing was determined via three non-consecutive 24-h dietary recalls. Sleep outcomes were objectively assessed using accelerometry. The eating window (time between first and last caloric intake), caloric midpoint (local time at which ≥ 50% of daily calories are consumed), eating jetlag (variability of the eating midpoint between non-working and working days), time from the midsleep point to first food intake, and time from last food intake to midsleep point were calculated. Body composition was determined by DXA. Blood pressure and fasting cardiometabolic risk factors (i.e., triglycerides, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, and insulin resistance) were measured. RESULTS: Meal timing was not associated with body composition (p > 0.05). The eating window was negatively related to HOMA-IR and cardiometabolic risk score in men (R2 = 0.348, ß = - 0.605; R2 = 0.234, ß = - 0.508; all p ≤ 0.003). The time from midsleep point to first food intake was positively related to HOMA-IR and cardiometabolic risk score in men (R2 = 0.212, ß = 0.485; R2 = 0.228, ß = 0.502; all p = 0.003). These associations remained after adjusting for confounders and multiplicity (all p ≤ 0.011). CONCLUSIONS: Meal timing seems unrelated to body composition in young adults. However, a longer daily eating window and a shorter time from midsleep point to first food intake (i.e., earlier first food intake in a 24 h cycle) are associated with better cardiometabolic health in young men. CLINICAL TRIAL REGISTRATION: NCT02365129 ( https://www. CLINICALTRIALS: gov/ct2/show/NCT02365129?term=ACTIBATE&draw=2&rank=1 ).

Different exercise training modalities similarly improve heart rate variability in sedentary middle-aged adults: the FIT-AGEING randomized controlled trial.

PURPOSE: This study aimed to investigate the influence of different exercise training modalities on heart rate variability (HRV) in sedentary middle-aged adults; and to study whether changes in health-related outcomes (i.e., body composition and cardiometabolic risk) are associated with those hypothetical HRV changes in sedentary middle-aged adults. METHODS: A total of 66 middle-aged adults (53.6 ± 4.4 years old; 50% women) were enrolled in the FIT-AGEING study. We conducted a 12-week randomized controlled trial. The participants were randomly assigned to 4 groups: (a) a control group (no exercise); (b) a physical activity recommendation from the World Health Organization group (PAR); (c) a high-intensity interval training group (HIIT); and (d) a high-intensity interval training group adding whole-body electromyostimulation (HIIT + EMS). RESULTS: All exercise training modalities induced changes in HRV parameters (all P ≤ 0.001) without statistical differences between them (all P > 0.05). We found associations between changes in body composition and cardiometabolic risk and exercise-related changes in HRV. CONCLUSION: Our results suggest that different exercise interventions (i.e., PAR, HIIT and HIIT + EMS) induced an enhancement of HRV in sedentary middle-aged adults. Our findings support the notion that exercise-related changes in HRV are associated with changes in body composition and cardiometabolic risk after the intervention program CLINICAL TRIAL REGISTRY: NCT03334357 (ClinicalTrials.gov). November 7, 2017 retrospectively registered.

Effect of Different Exercise Training Modalities on Fasting Levels of Oxylipins and Endocannabinoids in Middle-Aged Sedentary Adults: A Randomized Controlled Trial.

This study aimed to investigate the effects of different exercise training programs on fasting plasma levels of oxylipins, endocannabinoids (eCBs), and eCBs-like molecules in middle-aged sedentary adults. A 12-week randomized controlled trial was conducted using a parallel group design. Sixty-five middle-aged adults (40-65 years old) were randomly assigned to: (a) no exercise (control group), (b) concurrent training based on international physical activity recommendations (PAR group), (c) high-intensity interval training (HIIT group), and (d) HIIT together with whole-body electromyostimulation (HIIT + EMS group). Plasma levels of oxylipins, eCBs, and eCBs-like molecules were determined in plasma samples before and after the intervention using targeted lipidomics. Body composition was assessed through dual-energy X-ray absorptiometry, and dietary intake through a food frequency questionnaire and three nonconsecutive 24-hr recalls. The physical activity recommendations, HIIT, and HIIT-EMS groups showed decreased plasma levels of omega-6 and omega-3-derived oxylipins, and eCBs and eCBs-like molecules after 12 weeks (all Δ ≤ -0.12; all p < .05). Importantly, after Bonferroni post hoc corrections, the differences in plasma levels of omega-6 and omega-3 oxylipins were not statistically significant compared with the control group (all p > .05). However, after post hoc corrections, plasma levels of anandamide and oleoylethanolamide were increased in the physical activity recommendations group compared with the control group (anandamide: Δ = 0.05 vs. -0.09; oleoylethanolamide: Δ = -0.12 vs. 0.013, all p ≤ .049). In conclusion, this study reports that a 12-week exercise training intervention, independent of the modality applied, does not modify fasting plasma levels of omega-6 and omega-3 oxylipins, eCBs, and eCBs-like molecules in middle-aged sedentary adults.

Sleep and Anabolic/Catabolic Hormonal Profile in Sedentary Middle-Aged Adults: The FIT-AGEING Study.

Sleep quality plays an important role in the modulation of several aging markers. This influence could be explained by aging-induced hormonal changes. Indeed, poor sleep quality has been associated with the development of several endocrine-related health complications. This study examined the relationship of both subjective and objective sleep quantity and quality, with basal levels of selected plasma anabolic and catabolic hormones in sedentary middle-aged adults. A total of 74 volunteers (52.7% women; aged 53.7 ± 5.1) were recruited for this study. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI; higher scores indicate worse sleep quality), and objective sleep quality parameters (total sleep time [TST], wake after sleep onset [WASO], and sleep efficiency [SE]) were measured using a wrist-worn accelerometer. Basal levels of plasma dehydroepiandrosterone sulphate (DHEAS), total testosterone, sex hormone binding globulin (SHBG), somatotropin, and cortisol levels, were determined. Free testosterone was calculated from the total testosterone and SHBG levels. No associations of global PSQI score, TST, WASO, and SE with DHEAS, free testosterone, and somatotropin plasma levels were found, neither in men nor in women (all p ≥ 0.05). Global PSQI score was inversely related to cortisol plasma levels in women (p = 0.043). WASO was positively associated with cortisol plasma levels, while SE was negatively associated with cortisol plasma levels in women (all p ≤ 0.027). Sleep quality is not related to levels of plasma anabolic hormones, but to levels of catabolic hormones, in sedentary middle-aged adults. Therefore, these results suggest that potential changes in aging biomarkers associated with sleep disturbances, could be mediated by age-related changes in the catabolic endocrine system.

Effects of post-tetanic potentiation induced by whole-body electrostimulation and post-activation potentiation on maximum isometric strength.

It is currently unknown the most effective potentiation protocol to increase maximum strength. Hence, we investigated the separated and combined effects of post-tetanic potentiation (PTP) induced by whole-body electrostimulation (WB-EMS) and post-activation potentiation (PAP) induced by voluntary maximum isometric contractions on maximum isometric strength. Ten trained males were randomly evaluated on four occasions. In session A, maximum isometric strength (split squat) was measured in minutes 1, 4, and 8. In session B, the measurements were taken in minutes 2, 6, and 10. In session C, a WB-EMS protocol was applied to elicit PTP and the measurements were performed in minutes 1, 4, and 8. In session D, the same WB-EMS protocol was applied and the measurements were taken in minutes 2, 6, and 10. No significant differences in maximum isometric strength were observed between: (i) the control and WB-EMS in minutes 1 vs. 1 and 2 vs. 2; (ii) the control and PAP in minutes 1 vs. 4, 1 vs. 8, 2 vs. 6, and 2 vs. 10; and (iii) the PAP and WB-EMS plus PAP in minutes 4 vs. 4, 8 vs. 8, 6 vs. 6, and 10 vs. 10. In contrast, the WB-EMS plus PAP revealed a significant increase of 54% (~450 N) compared to the WB-EMS in minutes 4 and 8 compared to the minute 1 (p < 0.001), but not between minutes 2 vs. 6 and 2 vs. 10. The present results showed that PTP induced by WB-EMS in isolation or combined with PAP induced by voluntary maximum isometric contractions did not produce a significant increase in maximum isometric strength compared to the control and PAP alone, respectively.

Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta-analysis.

To determine the acute effect of a single high-intensity interval training (HIIT) session on testosterone and cortisol levels in healthy individuals, a systematic search of studies was conducted in MEDLINE and Web of Science databases from inception to February 2020. Meta-analyses were performed to establish the acute effect of HIIT on testosterone and cortisol levels immediately after a single HIIT session; after 30 min and 60 min (primary outcomes); and after 120 min, 180 min, and 24 h (secondary outcomes, only for pre-post intervention groups). Potential effect-size modifiers were assessed by meta-regression analyses and analyses of variance. Study quality was assessed using the Cochrane's risk of bias tool and the Physiotherapy Evidence Database scale. The meta-analyses of 10 controlled studies (213 participants) and 50 pre-post intervention groups (677 participants) revealed a significant increase in testosterone immediately after a single HIIT session (d = 0.92 and 0.52, respectively), which disappeared after 30 min (d = 0.18 and -0.04), and returned to baseline values after 60 min (d = -0.37 and -0.16). Significant increases of cortisol were found immediately after (d = 2.17 and 0.64), after 30 min (d = 1.62 and 0.67) and 60 min (d = 1.32 and 0.27). Testosterone and cortisol levels decreased significantly after 120 min (d = -0.48 and -0.95, respectively) and 180 min (d = -0.29 and -1.08), and returned to baseline values after 24 h (d = 0.14 and -0.02). HIIT components and participant's characteristics seem to moderate the effect sizes. In conclusion, testosterone and cortisol increase immediately after a single HIIT session, then drop below baseline levels, and finally return to baseline values after 24 h. This meta-analysis provides a better understanding of the acute endocrine response to a single HIIT session, which would certainly be valuable for both clinicians and coaches in the prescription of exercise programs to improve health and performance. Testosterone and cortisol may be used as sensitive biomarkers to monitor the anabolic and catabolic response to HIIT.

The effects of three types of exercise training on steroid hormones in physically inactive middle-aged adults: a randomized controlled trial.

PURPOSE: Physical inactivity and ageing are associated with imbalances in anabolic/catabolic steroid hormones, jeopardizing health. We investigated the effects of three types of training on plasma steroid hormone levels in physically inactive, middle-aged adults. METHODS: A 12-week randomized controlled trial was performed with a parallel-group design. A total of 67 (36 women) middle-aged adults (45-65 years old) were randomly assigned to (1) no exercise (control), (2) concurrent training based on the international physical activity recommendations (PAR), (3) high-intensity interval training (HIIT), or (4) HIIT plus whole-body electromyostimulation (HIIT + EMS). The training volume in the PAR group was 150 min/week at 60-65% of the heart rate reserve for aerobic training and ~ 60 min/week at 40-50% of the one-repetition maximum for resistance training. The training volume in the HIIT and HIIT + EMS groups was 40-65 min/week at > 95% of the maximum oxygen uptake in long interval sessions, and > 120% of the maximum oxygen uptake in short interval sessions. RESULTS: Compared to the control group, dehydroepiandrosterone sulfate increased in the PAR, HIIT, and HIIT + EMS groups (~ 14%, ~ 14%, and ~ 20%, respectively; all P < 0.01). Cortisol decreased in the PAR, HIIT, and HIIT + EMS groups (~ - 17%, ~ - 10%, and ~ - 23%, respectively; all P ≤ 0.05). Testosterone increased in the HIIT and HIIT + EMS groups (~ 28%, and ~ 16%, respectively; all P ≤ 0.01). Free testosterone increased in the HIIT and HIIT + EMS groups (~ 30% and ~ 18% respectively; all P ≤ 0.01). No significant increase in sex hormone-binding globulin was observed (P = 0.869). CONCLUSION: Our findings suggest that HIIT, with or without whole-body EMS, can significantly enhance steroid hormones status in previously physically inactive middle-aged adults. The PAR program led to slight improvements than the HIIT and HIIT + EMS groups despite the application of a higher training volume. CLINICAL TRIAL REGISTRY: NCT03334357 (ClinicalTrials.gov). November 7, 2017 retrospectively registered.

Docosahexaenoic acid protection against palmitic acid-induced lipotoxicity in NGF-differentiated PC12 cells involves enhancement of autophagy and inhibition of apoptosis and necroptosis.

Lipotoxicity (LTx) leads to cellular dysfunction and cell death and has been proposed to be an underlying process during traumatic and hypoxic injuries and neurodegenerative conditions in the nervous system. This study examines cellular mechanisms responsible for docosahexaenoic acid (DHA 22:6 n-3) protection in nerve growth factor-differentiated pheochromocytoma (NGFDPC12) cells from palmitic acid (PAM)-mediated lipotoxicity (PAM-LTx). NGFDPC12 cells exposed to PAM show a significant lipotoxicity demonstrated by a robust loss of cell viability, apoptosis, and increased HIF-1α and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 gene expression. Treatment of NGFDPC12 cells undergoing PAM-LTx with the pan-caspase inhibitor ZVAD did not protect, but shifted the process from apoptosis to necroptosis. This shift in cell death mechanism was evident by the appearance of the signature necroptotic Topo I protein cleavage fragments, phosphorylation of mixed lineage kinase domain-like, and inhibition with necrostatin-1. Cultures exposed to PAM and co-treated with necrostatin-1 (necroptosis inhibitor) and rapamycin (autophagy promoter), showed a significant protection against PAM-LTx compared to necrostatin-1 alone. In addition, co-treatment with DHA, as well as 20:5 n-3, 20:4 n-6, and 22:5 n-3, in the presence of PAM protected NGFDPC12 cells against LTx. DHA-induced neuroprotection includes restoring normal levels of HIF-1α and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 transcripts and caspase 8 and caspase 3 activity, phosphorylation of beclin-1, de-phosphorylation of mixed lineage kinase domain-like, increase in LC3-II, and up-regulation of Atg7 and Atg12 genes, suggesting activation of autophagy and inhibition of necroptosis. Furthermore, DHA-induced protection was suppressed by the lysosomotropic agent chloroquine, an inhibitor of autophagy. We conclude that DHA elicits neuroprotection by regulating multiple cell death pathways including enhancement of autophagy and inhibiting apoptosis and necroptosis.

Predictors of Sexual Desire and Sexual Function in Sedentary Middle-Aged Adults: The Role of Lean Mass Index and S-Klotho Plasma Levels. The FIT-AGEING Study.

BACKGROUND: Unhealthy lifestyle and aging negatively impact sexuality; consequently, the prevalence of sexual problems increases sharply in middle-aged adults, but the determinants of low sexual desire and sexual dysfunction are not fully elucidated. AIMS: To investigate the association of cardiometabolic profile, free testosterone plasma levels, body composition, physical fitness, and S-Klotho plasma levels with sexual desire and sexual function in middle-aged sedentary adults. METHODS: Seventy-four (39 women) sedentary middle-aged adults (45-65 years old) were recruited for the present cross-sectional study. OUTCOMES: The blood samples were collected in the morning (12 h of fasting) to determine cardiometabolic biomarkers and free testosterone and S-Klotho plasma levels. The cardiometabolic risk score was calculated based on the International Diabetes Federation's clinical criteria, quantitative insulin sensitivity check index, and homeostatic model assessment of insulin resistance index. A dual-energy X-ray absorptiometry scanner was used to determine the lean mass index (LMI) and the fat mass index. Maximal oxygen uptake was determined by a maximum treadmill test using indirect calorimetry. Muscular strength was measured with knee extensor isokinetic dynamometry (60° s-1). Sexual desire was assessed with the Sexual Desire Inventory 2. Sexual function was assessed with the Massachusetts General Hospital-Sexual Functioning Questionnaire. RESULTS: After age adjustment, free testosterone plasma levels were associated with solitary sexual desire in women (R2 = 0.193, ß = 0.342, P = .044). The LMI was associated with solitary sexual desire in men (R2 = 0.258, ß = 0.445, P = .024) and sexual function in women (R2 = 0.470, ß = -0.607, P < .001). S-Klotho plasma levels were associated with solitary sexual desire and sexual function in men (R2 = 0.412, ß = 0.817, P = .001; R2 = 0.193, ß = -0.659, P = .021, respectively) and with dyadic sexual desire and sexual function in women (R2 = 0.270, ß = 0.508, P = .020; R2 = 0.467, ß = -0.676, P < .001, respectively). CLINICAL IMPLICATIONS: S-Klotho plasma levels may represent a potential new biomarker for sexual desire and sexual function. Lean body mass development may benefit sexual desire and sexual function. STRENGTHS AND LIMITATIONS: Strengths include the analysis of novel and diverse biomarkers of health for sexual desire and sexual function. Limitations include the cross-sectional design and a relatively small sample size; thus, results should be interpreted cautiously and in the study population context. CONCLUSION: S-Klotho plasma levels were strongly associated with dyadic sexual desire, solitary sexual desire, and sexual function in sedentary middle-aged adults. The LMI was also positively associated with solitary sexual desire and sexual function in men and women, respectively. Dote-Montero M, De-la-O A, Castillo MJ, et al. Predictors of Sexual Desire and Sexual Function in Sedentary Middle-Aged Adults: The Role of Lean Mass Index and S-Klotho Plasma Levels. The FIT-AGEING Study. J Sex Med 2020;17:665-677.

Bridging energy bands to the crystalline and amorphous states of Si QDs.

The relationship between the crystallization process and opto-electronic properties of silicon quantum dots (Si QDs) synthesized by atmospheric pressure plasmas (APPs) is studied in this work. The synthesis of Si QDs is carried out by flowing silane as a gas precursor in a plasma confined to a submillimeter space. Experimental conditions are adjusted to propitiate the crystallization of the Si QDs and produce QDs with both amorphous and crystalline character. In all cases, the Si QDs present a well-defined mean particle size in the range of 1.5-5.5 nm. Si QDs present optical bandgaps between 2.3 eV and 2.5 eV, which are affected by quantum confinement. Plasma parameters evaluated using optical emission spectroscopy are then used as inputs for a collisional plasma model, whose calculations yield the surface temperature of the Si QDs within the plasma, justifying the crystallization behavior under certain experimental conditions. We measure the ultraviolet-visible optical properties and electronic properties through various techniques, build an energy level diagram for the valence electrons region as a function of the crystallinity of the QDs, and finally discuss the integration of these as active layers of all-inorganic solar cells.

Continuous In-Flight Synthesis for On-Demand Delivery of Ligand-Free Colloidal Gold Nanoparticles.

We demonstrate an entirely new method of nanoparticle chemical synthesis based on liquid droplet irradiation with ultralow (<0.1 eV) energy electrons. While nanoparticle formation via high energy radiolysis or transmission electron microscopy-based electron bombardment is well-understood, we have developed a source of electrons with energies close to thermal which leads to a number of important and unique benefits. The charged species, including the growing nanoparticles, are held in an ultrathin surface reaction zone which enables extremely rapid precursor reduction. In a proof-of-principle demonstration, we obtain small-diameter Au nanoparticles (∼4 nm) with tight control of polydispersity, in under 150 µs. The precursor was almost completely reduced in this period, and the resultant nanoparticles were water-soluble and free of surfactant or additional ligand chemistry. Nanoparticle synthesis rates within the droplets were many orders of magnitude greater than equivalent rates reported for radiolysis, electron beam irradiation, or colloidal chemical synthesis where reaction times vary from seconds to hours. In our device, a stream of precursor loaded microdroplets, ∼15 µm in diameter, were transported rapidly through a cold atmospheric pressure plasma with a high charge concentration. A high electron flux, electron and nanoparticle confinement at the surface of the droplet, and the picoliter reactor volume are thought to be responsible for the remarkable enhancement in nanoparticle synthesis rates. While this approach exhibits considerable potential for scale-up of synthesis rates, it also offers the more immediate prospect of continuous on-demand delivery of high-quality nanomaterials directly to their point of use by avoiding the necessity of collection, recovery, and purification. A range of new applications can be envisaged, from theranostics and biomedical imaging in tissue to inline catalyst production for pollution remediation in automobiles.

Association between Sleep Quality and Body Composition in Sedentary Middle-Aged Adults.

Background: Ageing is associated with sleep pattern changes and body composition changes, which are related to several diseases. Purpose: This study aimed to analyse the association between sleep quality and an extensive set of body composition parameters (waist-hip ratio, body mass index, bone mineral content, bone mineral density, lean mass, lean mass index, fat mass, fat mass percentage, fat mass index, visceral adipose tissue) and sleep quality in sedentary middle-aged adults. We also aimed to evaluate whether the possible associations accord between subjective and objective measurements of sleep quality. Methods: 74 (39 women) middle-aged sedentary adults (40⁻65 years old) participated in the present study. The sleep quality was assessed using the Pittsburgh sleep quality index (PSQI) scale and accelerometers. A PSQI global score more than 5 indicates poor sleep quality. Weight, height, waist and hip circumferences were measured, and body mass index and waist-hip ratio were also calculated. Body composition was assessed with a dual-energy X-ray absorptiometry scanner. Results: The PSQI global score was negatively associated with bone mineral content, bone mineral density, lean mass, lean mass index and positively associated with fat mass percentage. No association was found between accelerometer parameters and body composition variables. Conclusion: We showed that a subjective poor sleep quality was negatively associated with bone mineral content (BMC), bone mineral density (BMD), lean mass and lean mass index (LMI) whereas was positively associated with fat mass percentage in middle-aged adults. We also observed that these associations did not accord with objective sleep quality measurements.

In Situ Determination of the Water Condensation Mechanisms on Superhydrophobic and Superhydrophilic Titanium Dioxide Nanotubes.

One-dimensional (1D) nanostructured surfaces based on high-density arrays of nanowires and nanotubes of photoactive titanium dioxide (TiO2) present a tunable wetting behavior from superhydrophobic to superhydrophilic states. These situations are depicted in a reversible way by simply irradiating with ultraviolet light (superhydrophobic to superhydrophilic) and storage in dark. In this article, we combine in situ environmental scanning electron microscopy (ESEM) and near ambient pressure photoemission analysis (NAPP) to understand this transition. These experiments reveal complementary information at microscopic and atomic level reflecting the surface wettability and chemical state modifications experienced by these 1D surfaces upon irradiation. We pay special attention to the role of the water condensation mechanisms and try to elucidate the relationship between apparent water contact angles of sessile drops under ambient conditions at the macroscale with the formation of droplets by water condensation at low temperature and increasing humidity on the nanotubes' surfaces. Thus, for the as-grown nanotubes, we reveal a metastable and superhydrophobic Cassie state for sessile drops that tunes toward water dropwise condensation at the microscale compatible with a partial hydrophobic Wenzel state. For the UV-irradiated surfaces, a filmwise wetting behavior is observed for both condensed water and sessile droplets. NAPP analyses show a hydroxyl accumulation on the as-grown nanotubes surfaces during the exposure to water condensation conditions, whereas the water filmwise condensation on a previously hydroxyl enriched surface is proved for the superhydrophilic counterpart.

Acute effect of static exercise in patients with aortic regurgitation assessed by cardiovascular magnetic resonance: role of left ventricular remodelling.

OBJECTIVE: In patients with aortic regurgitation (AR), the effect of static exercise (SE) on global ventricular function and AR severity has not been previously studied. METHODS: Resting and SE cardiovascular magnetic resonance (CMR) were prospectively performed in 23 asymptomatic patients with AR. RESULTS: During SE, we observed a decrease in regurgitant volume in both end-diastolic (EDV) and end-systolic (ESV) volume in both ventricles, as well as a slight decrease in LV ejection fraction (EF). Interestingly, responses varied depending on the degree of LV remodelling. Among patients with a greater degree of LV remodelling, we observed a decrease in LVEF (56 ± 4 % at rest vs 48 ± 7 % during SE, p = 0.001) as a result of a lower decrease in LVESV (with respect to LVEDV. Among patients with a lower degree of LV remodelling, LVEF remained unchanged. RVEF remained unchanged in both groups. CONCLUSIONS: In patients with AR, SE provoked a reduction in preload, LV stroke volume, and regurgitant volume. In those patients with higher LV remodelling, we observed a decrease in LVEF, suggesting a lower LV contractile reserve. KEY POINTS: • In patients with aortic regurgitation, static exercise reduced preload volume. • In patients with aortic regurgitation, static exercise reduced stroke volume. • In patients with aortic regurgitation, static exercise reduced regurgitant volume. • In patients with greater remodelling, static exercise unmasked a lower contractile reserve. • Effect of static exercise on aortic regurgitation was assessed by cardiac MR.

Peptide functionalized gold nanoparticles: the influence of pH on binding efficiency.

We report herein on the synthesis of mixed monolayer gold nanoparticles (AuNPs) capped with both polyethylene glycol (PEG) and one of three peptides. Either a receptor-mediated endocytosis peptide, an endosomal escape pathway (H5WYG) peptide or the Nrp-1 targeting RGD peptide (CRGDK) labeled with FITC. All three peptides have a thiol containing cysteine residue which can be used to bind the peptides to the AuNPs. In order to investigate the influence of pH on peptide attachment, PEGylated AuNPs were centrifuged, the supernatant removed, and the nanoparticles were then re-suspended in a range of pH buffer solutions above, below and at the respective isoelectric points of the peptides before co-functionalization. Peptide attachment was investigated using dynamic light scattering, Ultra-violet visible spectroscopy (UV/Vis), FTIR and photo luminescence spectroscopy. UV/Vis analysis coupled with protein assay results and photoluminescence of the FITC tagged RGD peptide concluded that a pH of ∼8 optimized the cysteine binding and stability, irrespective of the peptide used.

Epidermal fatty acid-binding protein protects nerve growth factor-differentiated PC12 cells from lipotoxic injury.

Epidermal fatty acid-binding protein (E-FABP/FABP5/DA11) binds and transport long-chain fatty acids in the cytoplasm and may play a protecting role during neuronal injury. We examined whether E-FABP protects nerve growth factor-differentiated PC12 cells (NGFDPC12 cells) from lipotoxic injury observed after palmitic acid (C16:0; PAM) overload. NGFDPC12 cells cultures treated with PAM/bovine serum albumin at 0.3 mM/0.15 mM show PAM-induced lipotoxicity (PAM-LTx) and apoptosis. The apoptosis was preceded by a cellular accumulation of reactive oxygen species (ROS) and higher levels of E-FABP. Antioxidants MCI-186 and N-acetyl cysteine prevented E-FABP's induction in expression by PAM-LTx, while tert-butyl hydroperoxide increased ROS and E-FABP expression. Non-metabolized methyl ester of PAM, methyl palmitic acid (mPAM), failed to increase cellular ROS, E-FABP gene expression, or trigger apoptosis. Treatment of NGFDPC12 cultures with siE-FABP showed reduced E-FABP levels correlating with higher accumulation of ROS and cell death after exposure to PAM. In contrast, increasing E-FABP cellular levels by pre-loading the cells with recombinant E-FABP diminished the PAM-induced ROS and cell death. Finally, agonists for PPARß (GW0742) or PPARγ (GW1929) increased E-FABP expression and enhanced the resistance of NGFDPC12 cells to PAM-LTx. We conclude that E-FABP protects NGFDPC12 cells from lipotoxic injury through mechanisms that involve reduction of ROS. Epidermal fatty acid-binding protein (E-FABP) may protect nerve cells from the damaging exposure to high levels of free fatty acids (FA). We show that E-FABP can neutralize the effects of reactive oxygen species (ROS) generated by the high levels of FA in the cell and protect PC12 cells from lipotoxic injuries common in Type 2 diabetes neuropathy. Potentially, E-FABP gene up-regulation may be mediated through the NFkB pathway and future studies are needed to further evaluate this proposition.

Acute effect of static exercise on the cardiovascular system: assessment by cardiovascular magnetic resonance.

PURPOSE: The acute effect of static exercise on the global dynamics of the cardiovascular system is poorly understood. The use of cardiovascular magnetic resonance (CMR) may be useful for evaluating this effect. METHODS: A total of 12 healthy individuals underwent CMR imaging at rest and while performing a maximal sustained static exercise (weight elevation with both legs). We analyzed the effects on left and right ventricular function, ascending aorta dynamics, and venous capacitance using standard cine and phase-contrast sequences. RESULTS: We observed excellent reproducibility in the measurements of the images obtained at rest as well as during static exercise. During exercise, we observed reduced left (-35 ± 8 %, p < 0.001) and right (-44 ± 9 %, p < 0.001) ventricle end-diastolic volumes, reduced left (-35 ± 16 %, p < 0.001) and right (-43 ± 8 %, p < 0.001) ventricle end-systolic volumes (both with a significantly greater reduction in the right ventricle), a reduced superior vena cava cross-sectional area (-20 ± 17 %, p = 0.003), and increased left ventricle wall thickness. We estimated that there was an increase in left ventricle contractility. There were no significant changes in the left and right ventricular ejection fractions. During exercise, we noted a tendency toward decreased aortic distensibility and a reduction of ascending aorta systolic expansion. CONCLUSIONS: In healthy individuals, an acute maximal static exercise produced a reduction in the left ventricle, right ventricle, and superior vena cava volumes as well as signs of increased aortic stiffness without increasing left ventricular systolic wall stress. CMR is feasible and useful in evaluating the hemodynamic effects of static exercise.

Sucrose synthase activity in the sus1/sus2/sus3/sus4 Arabidopsis mutant is sufficient to support normal cellulose and starch production.

Sucrose synthase (SUS) catalyzes the reversible conversion of sucrose and a nucleoside diphosphate into the corresponding nucleoside diphosphate-glucose and fructose. In Arabidopsis, a multigene family encodes six SUS (SUS1-6) isoforms. The involvement of SUS in the synthesis of UDP-glucose and ADP-glucose linked to Arabidopsis cellulose and starch biosynthesis, respectively, has been questioned by Barratt et al. [(2009) Proc Natl Acad Sci USA 106:13124-13129], who showed that (i) SUS activity in wild type (WT) leaves is too low to account for normal rate of starch accumulation in Arabidopsis, and (ii) different organs of the sus1/sus2/sus3/sus4 SUS mutant impaired in SUS activity accumulate WT levels of ADP-glucose, UDP-glucose, cellulose and starch. However, these authors assayed SUS activity under unfavorable pH conditions for the reaction. By using favorable pH conditions for assaying SUS activity, in this work we show that SUS activity in the cleavage direction is sufficient to support normal rate of starch accumulation in WT leaves. We also demonstrate that sus1/sus2/sus3/sus4 leaves display WT SUS5 and SUS6 expression levels, whereas leaves of the sus5/sus6 mutant display WT SUS1-4 expression levels. Furthermore, we show that SUS activity in leaves and stems of the sus1/sus2/sus3/sus4 and sus5/sus6 plants is ∼85% of that of WT leaves, which can support normal cellulose and starch biosynthesis. The overall data disprove Barratt et al. (2009) claims, and are consistent with the possible involvement of SUS in cellulose and starch biosynthesis in Arabidopsis.