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Effect on splanchnic oxygenation of breast milk, fortified breast milk, and formula milk in preterm infants.
Dani, C, Coviello, C, Montano, S, Remaschi, G, Petrolini, C, Strozzi, MC, Maggiora, E, Sabatini, M, Gazzolo, D
Pediatric research. 2021;(1):171-174
Abstract
BACKGROUND Enteral feeding induces mesenteric hemodynamic changes in preterm infants, which may vary according to the milk used. Our aim in this study was to evaluate changes of splanchnic regional oxygenation (rSO2S) measured by near-infrared spectroscopy (NIRS) in infants fed with mother's own milk (MOM), fortified human milk (FHM), or preterm formula (PTF). METHODS Infants born at 25-31 weeks of gestational age (n = 54) received a bolus of MOM, FHM, or PTF. rSO2S and splanchnic fractional oxygen extraction ratio (FOES) were recorded 60 min before (T0), and 30 min (T1) and 120 min (T2) after the beginning of bolus feeding. RESULTS In the MOM group, rSO2S and FOES did not change during the study period. In the FBM group, rSO2S decreased from T0 to T1 and increased from T1 to T2, while FOES changed in reverse. In the PTF group, rSO2S decreased from T0 to T1 and from T1 to T2, while FOES changed in reverse. CONCLUSIONS Splanchnic oxygenation was not affected by MOM feeding, was transiently decreased by FBM feeding, and was persistently decreased by PTF. These results suggest that preterm infants who received PTF has higher splanchnic tissue oxygen extraction compared to those who received MOM or FBM. IMPACT Human milk feeding is associated to a lower splanchnic energy expenditure than preterm formula feeding. Fortified human milk transiently increases splanchnic energy expenditure. Preterm formula should be used only in the absence of human milk.
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Impact of Carbohydrate Ingestion on Cognitive Flexibility and Cerebral Oxygenation during High-Intensity Intermittent Exercise: A Comparison between Maple Products and Usual Carbohydrate Solutions.
Dupuy, O, Tremblay, J
Nutrients. 2019;(9)
Abstract
BACKGROUND The aim of this study was to compare the effects of carbohydrate (CHO) drinks (6% per volume) sweetened with maple (syrup or sap) to a commercial sports drink, glucose, and a control solution (water) on cognitive flexibility during high-intensity intermittent exercise. METHODS Eighty-five active men completed six 3-min bouts at 95% of their maximal aerobic power on a stationary bike, with 3 min of passive rest between efforts. Subjects were randomly allocated to an ingestion condition. Following each exercise bout, subjects ingested 166 mL of the experimental solution, drinking a total of 1 L of the same solution throughout the experimentation. Cognitive flexibility was measured using reaction time and accuracy on the Stroop task. The cognitive task was performed a total of 10 times, including 15 and 30 min post-exercise. Glycemia and cerebral oxygenation were also measured at each time point. Statistical analyses were performed using a two-way ANOVA (Condition × Time) with repeated measures. RESULTS The ingestion of maple products and the commercial sports drink led to a lesser increase in glycemia than glucose ingestion. CHO ingestion, when compared to water, induced a slight reduction in reaction times on the cognitive task, especially in the switching trials. CHO ingestion had no impact on cerebral oxygenation. CONCLUSIONS This study shows that CHO ingestion, regardless of its type, tends to improve cognitive performance throughout exercise, especially during difficult cognitive tasks.
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Spectroscopic and Reactivity Comparisons between Nonheme Oxoiron(IV) and Oxoiron(V) Species Bearing the Same Ancillary Ligand.
Dantignana, V, Serrano-Plana, J, Draksharapu, A, Magallón, C, Banerjee, S, Fan, R, Gamba, I, Guo, Y, Que, L, Costas, M, et al
Journal of the American Chemical Society. 2019;(38):15078-15091
Abstract
This work directly compares the spectroscopic and reactivity properties of an oxoiron(IV) and an oxoiron(V) complex that are supported by the same neutral tetradentate N-based PyNMe3 ligand. A complete spectroscopic characterization of the oxoiron(IV) species (2) reveals that this compound exists as a mixture of two isomers. The reactivity of the thermodynamically more stable oxoiron(IV) isomer (2b) is directly compared to that exhibited by the previously reported 1e--oxidized analogue [FeV(O)(OAc)(PyNMe3)]2+ (3). Our data indicates that 2b is 4 to 5 orders of magnitude slower than 3 in hydrogen atom transfer (HAT) from C-H bonds. The origin of this huge difference lies in the strength of the O-H bond formed after HAT by the oxoiron unit, the O-H bond derived from 3 being about 20 kcal·mol-1 stronger than that from 2b. The estimated bond strength of the FeIVO-H bond of 100 kcal·mol-1 is very close to the reported values for highly active synthetic models of compound I of cytochrome P450. In addition, this comparative study provides direct experimental evidence that the lifetime of the carbon-centered radical that forms after the initial HAT by the high valent oxoiron complex depends on the oxidation state of the nascent Fe-OH complex. Complex 2b generates long-lived carbon-centered radicals that freely diffuse in solution, while 3 generates short-lived caged radicals that rapidly form product C-OH bonds, so only 3 engages in stereoretentive hydroxylation reactions. Thus, the oxidation state of the iron center modulates not only the rate of HAT but also the rate of ligand rebound.
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A randomized pilot study comparing the role of PEEP, O2 flow, and high-flow air for weaning of ventilatory support in very low birth weight infants.
Yang, CY, Yang, MC, Chu, SM, Chiang, MC, Lien, R
Pediatrics and neonatology. 2018;(2):198-204
Abstract
BACKGROUND There is a lack of evidence to guide step-wise weaning of positive pressure respiratory support for premature infants. This study sought to compare the efficacy of three weaning protocols we designed to facilitate weaning of very low birth weight (VLBW, less than 1500 g) preterm infants from nasal continuous positive airway pressure (NCPAP) support. METHODS This was a prospective, randomized, controlled trial of VLBW preterm infants who received positive pressure ventilatory support in our neonatal intensive care unit (NICU) from April 2008 through March 2009. When these infants were weaned to CPAP as their last step of respiratory support, they would be randomly assigned to one of the following three groups as their further weaning methods (M): (M1) CPAP group, (M2) O2 flow group, and (M3) air flow group. The time period they needed to wean off any kind of respiratory support, as well as the likelihood of developing relevant prematurity related morbidities, were compared among patients using different weaning modalities. RESULTS 181 patients were enrolled in the study. Their gestational age (GA) and birth weight (BW) were 29.1 ± 2.5, 28.7 ± 2.4, 28.7 ± 2.4 (mean ± SD) weeks and 1142 ± 232, 1099 ± 234, 1083 ± 219 g, in M1, M2 and M3, respectively. The time (period) needed to wean off support was 16.0 ± 10.0 days (M1), 11.6 ± 6.4 days (M2), and 15.0 ± 8.9 days (M3), respectively (p = .033). Incidence of retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) were both significantly higher in the O2 flow group (p = .048). CONCLUSIONS Although using low oxygen flow significantly shortens CPAP weaning time, it may increase risks of BPD and ROP, both known to be related to oxygen toxicity. Unless the infant has BPD and is O2-dependent, clinicians should consider using air flow or just splinting with no support at all when weaning NCPAP.
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Randomized controlled trial of low (5%) versus ultralow (2%) oxygen for extended culture using bipronucleate and tripronucleate human preimplantation embryos.
Kaser, DJ, Bogale, B, Sarda, V, Farland, LV, Williams, PL, Racowsky, C
Fertility and sterility. 2018;(6):1030-1037.e2
Abstract
OBJECTIVE To determine whether [1] exposure of embryos to 5% oxygen (O2) from day 1 (D1) to D3, and then to 2% O2 from D3 to D5, improves total blastocyst yield, as compared with continuous exposure to 5% O2; and [2] extended culture in 2% O2 alters key metabolic processes and O2-regulated gene expression in human preimplantation embryos. DESIGN Randomized controlled trial. SETTING Academic medical center. PATIENT(S): Bipronucleate and tripronucleate embryos donated for research. INTERVENTION(S): On D1, sibling zygotes were randomized to culture in 5% O2 from D1 to D5 (n = 102; "5% group") or 5% O2 from D1 to D3, then 2% O2 from D3 to D5 (n = 101, "2% group"). MAIN OUTCOME MEASURE(S): Developmental stage and grade; D5 total cell counts; mass spectrometry of spent media; quantitative polymerase chain reaction of 21 genes in inner cell mass and trophectoderm. RESULT(S): Among cleaved embryos (n = 176, 87%), those in the 2% group were less likely to arrest at the cleavage stage on D5 (34 of 87, 39.1%) compared with the 5% group (52 of 89, 58.4%) (adjusted odds ratio 0.38, 95% confidence interval 0.18-0.80). Those in the 2% group were more likely to blastulate (35 of 87, 40.2%) than those in the 5% group (20 of 89, 22.5%) (adjusted odds ratio 2.55, 95% confidence interval 1.27-5.12). Culture in 2% O2 was associated with significantly fewer cells in early and advanced blastocysts, alteration in relative abundances of anabolic amino acids and metabolites involved in redox homeostasis, and differential expression of MUC1 in trophectoderm. CONCLUSION(S): These findings provide foundational evidence for future investigation of 2% O2 as the preferred O2 tension for extended culture of human embryos.
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Comparison between Experimental and Broken Symmetry Density Functional Theory (BS-DFT) Calculated Electron Paramagnetic Resonance (EPR) Parameters of the S2 State of the Oxygen-Evolving Complex of Photosystem II in Its Native (Calcium) and Strontium-Substituted Form.
Beal, NJ, Corry, TA, O'Malley, PJ
The journal of physical chemistry. B. 2017;(50):11273-11283
Abstract
A comparison between experimental and Broken Symmetry Density Functional theory (BS-DFT) calculated hyperfine couplings for the S2 state of the oxygen-evolving complex (OEC) has been performed. The effect of Ca substitution by Sr combined with the protonation state of two terminal hydroxo or aqua ligands, W1 and W2, on the calculated hyperfine couplings of 55Mn, 13C, 14N, 17O, and 1H nuclei has been investigated. Our findings show best agreement with experiment for OEC models which contain a hydroxide group at the W2 position and a water molecule at W1. For this model the agreement between calculated and experimental data for all hyperfine couplings is excellent. Models with a hydroxide group at W1 are particularly poor models. Sr substitution has a minor influence on calculated hyperfine couplings in agreement with experimental determinations. The sensitivity of the hyperfine couplings to relatively minor changes in the OEC structure demonstrates the power of this methodology in refining the details of its steric and electronic structure which is an essential step in formulating a complete mechanism for water oxidation by the OEC.
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Effect of caffeine ingestion on anaerobic capacity quantified by different methods.
Arcoverde, L, Silveira, R, Tomazini, F, Sansonio, A, Bertuzzi, R, Lima-Silva, AE, Andrade-Souza, VA
PloS one. 2017;(6):e0179457
Abstract
We investigated whether caffeine ingestion before submaximal exercise bouts would affect supramaximal oxygen demand and maximal accumulated oxygen deficit (MAOD), and if caffeine-induced improvement on the anaerobic capacity (AC) could be detected by different methods. Nine men took part in several submaximal and supramaximal exercise bouts one hour after ingesting caffeine (5 mg·kg-1) or placebo. The AC was estimated by MAOD, alternative MAOD, critical power, and gross efficiency methods. Caffeine had no effect on exercise endurance during the supramaximal bout (caffeine: 131.3 ± 21.9 and placebo: 130.8 ± 20.8 s, P = 0.80). Caffeine ingestion before submaximal trials did not affect supramaximal oxygen demand and MAOD compared to placebo (7.88 ± 1.56 L and 65.80 ± 16.06 kJ vs. 7.89 ± 1.30 L and 62.85 ± 13.67 kJ, P = 0.99). Additionally, MAOD was similar between caffeine and placebo when supramaximal oxygen demand was estimated without caffeine effects during submaximal bouts (67.02 ± 16.36 and 62.85 ± 13.67 kJ, P = 0.41) or when estimated by alternative MAOD (56.61 ± 8.49 and 56.87 ± 9.76 kJ, P = 0.91). The AC estimated by gross efficiency was also similar between caffeine and placebo (21.80 ± 3.09 and 20.94 ± 2.67 kJ, P = 0.15), but was lower in caffeine when estimated by critical power method (16.2 ± 2.6 vs. 19.3 ± 3.5 kJ, P = 0.03). In conclusion, caffeine ingestion before submaximal bouts did not affect supramaximal oxygen demand and consequently MAOD. Otherwise, caffeine seems to have no clear positive effect on AC.
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Assessing the effects of a short-term green tea intervention in skin microvascular function and oxygen tension in older and younger adults.
Wasilewski, R, Ubara, EO, Klonizakis, M
Microvascular research. 2016;:65-71
Abstract
Green tea consumption has been associated with a reduction in cardiovascular disease risk factors. However, there is little evidence examining its potential differing effect between younger and older populations, whilst little is known on its effect on the circulatory system when oxygen demand is higher. Therefore the aim of this study was to evaluate the short-term effects of green tea consumption on microvascular functioning in both an older and younger population. Fifteen young [24 (4.0)] and fifteen older [61 (4.0)] participants, consumed two cups of green tea daily for 14days. We used Laser Doppler Flowmetry (LDF) to assess cutaneous microvascular function and Transcutaneous Oxygen monitoring (TcPO2) to assess skin oxygen tension. Systolic and diastolic blood pressure were also assessed on both visits. We observed significant improvements in axon-mediated microvascular vasodilation for the younger group [1.6 (0.59) vs 2.05 (0.72), p<0.05] and the older group [1.25 (0.58) vs 1.65 (0.5) p<0.05]. Improvements in skin oxygen tension were also noted for both groups in both noted TcPO2 measures (i.e. 1.25 (0.58) vs 1.65 (0.5) (p<0.05), for ΔTcPO2max for the older group, between visits) respectively. Improvements were also observed for systolic blood pressure in both the younger [120 (10) vs 112 (10), p<0.05] and older group [129 (12) v 124 (11), p<0.001]. In conclusion, we observed statistically-significant improvements in microvascular function and skin oxygen tension. Our results suggest that green tea may prove beneficial as a dietary element in lifestyle interventions aiming to lower cardiovascular disease risk, in both older and younger populations.
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9.
In vivo imaging of eribulin-induced reoxygenation in advanced breast cancer patients: a comparison to bevacizumab.
Ueda, S, Saeki, T, Takeuchi, H, Shigekawa, T, Yamane, T, Kuji, I, Osaki, A
British journal of cancer. 2016;(11):1212-8
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Abstract
BACKGROUND Eribulin mesylate (eribulin) is a first-in-class halichondrin B-based microtubule dynamics inhibitor. To compare the anti-angiogenic activity of eribulin to that of bevacizumab, we compared tumour vessel remodelling and reoxygenation between the two agents. METHODS Patients with advanced breast cancer with stage III/IV were eligible for the study. Patients were assigned to receive either eribulin or single-agent bevacizumab. Tissue concentrations of oxyhaemoglobin (O2Hb) and deoxyhaemoglobin (HHb), and oxygen saturation (SO2) of breast tumours before and day 7 after the first infusion were repeatedly measured using diffuse optical spectroscopic imaging (DOSI). A pair of blood samples was collected for multiplex biomarker studies. RESULTS Baseline DOSI measurement of all 29 patients (eribulin, n=14 and bevacizumab, n=15) revealed significantly higher tumour concentrations of O2Hb and HHb than that in the normal breast tissue. After eribulin treatment, DOSI revealed a significant decrease in HHb concentration and increased SO2 during the observation period. This trend was not observed for bevacizumab. Instead, bevacizumab significantly decreased the concentration of O2Hb. The multiplex biomarker study revealed that both eribulin and bevacizumab decreased plasma concentrations of VEGF and bFGF, but only eribulin treatment suppressed the plasma concentration of TGF-β1. CONCLUSIONS Eribulin, but not bevacizumab, treatment increased tumour SO2. Suppression of TGF-β1 by eribulin could have a favourable anti-angiogenic effect. Our results suggest that differences in vascular remodelling between these two agents may account for their different effects on tumour reoxygenation.
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Appetite and gut hormone responses to moderate-intensity continuous exercise versus high-intensity interval exercise, in normoxic and hypoxic conditions.
Bailey, DP, Smith, LR, Chrismas, BC, Taylor, L, Stensel, DJ, Deighton, K, Douglas, JA, Kerr, CJ
Appetite. 2015;:237-45
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Abstract
This study investigated the effects of continuous moderate-intensity exercise (MIE) and high-intensity interval exercise (HIIE) in combination with short exposure to hypoxia on appetite and plasma concentrations of acylated ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). Twelve healthy males completed four, 2.6 h trials in a random order: (1) MIE-normoxia, (2) MIE-hypoxia, (3) HIIE-normoxia, and (4) HIIE-hypoxia. Exercise took place in an environmental chamber. During MIE, participants ran for 50 min at 70% of altitude-specific maximal oxygen uptake (V˙O2max) and during HIIE performed 6 × 3 min running at 90% V˙O2max interspersed with 6 × 3 min active recovery at 50% V˙O2max with a 7 min warm-up and cool-down at 70% V˙O2max (50 min total). In hypoxic trials, exercise was performed at a simulated altitude of 2980 m (14.5% O2). Exercise was completed after a standardised breakfast. A second meal standardised to 30% of participants' daily energy requirements was provided 45 min after exercise. Appetite was suppressed more in hypoxia than normoxia during exercise, post-exercise, and for the full 2.6 h trial period (linear mixed modelling, p <0.05). Plasma acylated ghrelin concentrations were lower in hypoxia than normoxia post-exercise and for the full 2.6 h trial period (p <0.05). PYY concentrations were higher in HIIE than MIE under hypoxic conditions during exercise (p = 0.042). No differences in GLP-1 were observed between conditions (p > 0.05). These findings demonstrate that short exposure to hypoxia causes suppressions in appetite and plasma acylated ghrelin concentrations. Furthermore, appetite responses to exercise do not appear to be influenced by exercise modality.