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Does Low-Level Laser Therapy Decrease Muscle-Damaging Mediators After Performance in Soccer Athletes Versus Sham Laser Treatment? A Critically Appraised Topic.
Bettleyon, J, Kaminski, TW
Journal of sport rehabilitation. 2020;(8):1210-1213
Abstract
Clinical Scenario: Low-level laser therapy (LLLT) is a controversial topic for its use in athletic recovery, mainly due to inconsistency in research regarding the application of LLLT. Articles on LLLT have assessed its effectiveness in untrained humans through pain scales, functional scales, and blood draws, and it has been found capable in nonathletic rehabilitative use. The controversy lies with LLLT in the recovering athlete. Not only do athletes need to perform at high levels, but each sport is unique in the metabolic demands placed on the athletes' bodies. This modality can alter chemical mediators of the inflammatory process, specifically blood lactate (BL) and creatine kinase (CK). During soccer contests, it is a common problem for athletes to have an average CK level of 800 U/L and BL of 8 mmol·L, increasing delayed-onset muscle soreness and fatigue. Micro-CK level elevation is associated with cellular membrane damage, localized hypoxia, and electrolyte imbalances, hindering the recovery process. Clinical Question: Does LLLT decrease muscle-damaging mediators effecting player fatigue and delayed-onset muscle soreness after performance in soccer athletes versus sham treatment? Summary of Key Findings: In 3 studies, preperformance, postperformance, or preperformance and postperformance LLLT was performed and evaluated BL (2 of 3) and CK (2 of 3). In each article, BL and CK showed a significant decrease (P < .05) when performed either preperformance or postperformance versus the control group. The greatest decrease in these mediators was noticed when postperformance laser therapy was performed. Clinical Bottom Line: LLLT at 10, 30, or 50 J performed at a minimum of 2 locations on the rectus femoris, vastus lateralis, and vastus medialis bilaterally for 10 seconds each is significant in decreasing blood serum levels of BL and CK when performed postexercise. Strength of Recommendations: All 3 articles obtained a Physiotherapy Evidence Database score of ≥8/10.
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Combination of organic acids and low-dose gamma irradiation as antimicrobial treatment to inactivate Shiga toxin-producing Escherichia coli inoculated in beef trimmings: Lack of benefits in relation to single treatments.
Cap, M, Cingolani, C, Lires, C, Mozgovoj, M, Soteras, T, Sucari, A, Gentiluomo, J, Descalzo, A, Grigioni, G, Signorini, M, et al
PloS one. 2020;(3):e0230812
Abstract
The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids alone were not effective in reducing STEC populations. For high inoculum samples, the most effective treatment was HDI followed by LDI+LA and LDI alone or combined with CA. For low inoculum samples, the most effective treatment was HDI followed by LDI alone or combined with organic acids. Concerning meat quality parameters and sensory attributes, irradiation treatments (LDI and HDI) caused minimal changes, while LDI+LA modified them significantly compared with the control. Therefore, based on our results, no benefits were observed after combining organic acids with gamma irradiation.
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Lactate in Sarcoma Microenvironment: Much More than just a Waste Product.
Taddei, ML, Pietrovito, L, Leo, A, Chiarugi, P
Cells. 2020;(2)
Abstract
Sarcomas are rare and heterogeneous malignant tumors relatively resistant to radio- and chemotherapy. Sarcoma progression is deeply dependent on environmental conditions that sustain both cancer growth and invasive abilities. Sarcoma microenvironment is composed of different stromal cell types and extracellular proteins. In this context, cancer cells may cooperate or compete with stromal cells for metabolic nutrients to sustain their survival and to adapt to environmental changes. The strict interplay between stromal and sarcoma cells deeply affects the extracellular metabolic milieu, thus altering the behavior of both cancer cells and other non-tumor cells, including immune cells. Cancer cells are typically dependent on glucose fermentation for growth and lactate is one of the most heavily increased metabolites in the tumor bulk. Currently, lactate is no longer considered a waste product of the Warburg metabolism, but novel signaling molecules able to regulate the behavior of tumor cells, tumor-stroma interactions and the immune response. In this review, we illustrate the role of lactate in the strong acidity microenvironment of sarcoma. Really, in the biological context of sarcoma, where novel targeted therapies are needed to improve patient outcomes in combination with current therapies or as an alternative treatment, lactate targeting could be a promising approach to future clinical trials.
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Beta alanine supplementation effects on metabolic contribution and swimming performance.
Norberto, MS, Barbieri, RA, Bertucci, DR, Gobbi, RB, Campos, EZ, Zagatto, AM, De Freitas, EC, Papoti, M
Journal of the International Society of Sports Nutrition. 2020;(1):40
Abstract
BACKGROUND Investigations of β-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of β-alanine supplementation on metabolic contribution and performance during 400-m swim. METHODS Thirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day- 1 of β-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La-]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl). RESULTS No differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89). CONCLUSIONS Thus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and β-alanine supplementation doesn't affect metabolic contribution and performance during 400-m freestyle.
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Higher Postdialysis Lactic Acid Is Associated with Postdialysis Fatigue in Maintenance of Hemodialysis Patients.
Zu, Y, Lu, X, Yu, Q, Yu, L, Li, H, Wang, S
Blood purification. 2020;(5):535-541
Abstract
BACKGROUND Postdialysis fatigue (PDF) is not an unusual symptom among hemodialysis (HD) patients; however, its causes remain unclear. The aim of this study was to analyze the factors responsible for PDF in maintenance HD patients. METHODS This was a single-center cross-sectional study conducted between March 2018 and March 2019 at the Department of Blood Purification, Beijing Chao-Yang Hospital, Capital Medical University. One hundred and fifteen HD patients were enrolled. Clinical data on demographics, comorbidities, and the primary cause of end-stage renal disease were obtained by questionnaires. Laboratory data were collected pre- and post-HD. Participants were divided into 3 groups according to PDF degree. RESULTS The prevalence of PDF in participants was 60% (n = 69); 26.09% had mild PDF; and 33.91% had severe PDF. In the severe PDF group, the prevalence of intradialytic hypotension (IDH) was 38.46%, significantly higher than in the no PDF group (no-PDF; 8.70%) and mild-PDF (16.67%; p = 0.01 for both) groups. In the severe-PDF group, Charlson comorbidity index score and ultrafiltration rate were significantly higher than those in the no-PDF group (p = 0.040, p = 0.020, respectively). In the severe-PDF group, postdialysis lactic acid (Lac) level was significantly higher than that in the no-PDF or mild-PDF groups (p = 0.013 for both). And in the severe-PDF group, postdialysis sodium (Na) was significantly lower than that in the no-PDF or mild-PDF groups (p = 0.026 for both). It was shown by unconditional logistic regression analysis that IDH occurrence (OR 3.821, 95% CI 1.330-10.975), ultrafiltration rates (OR 1.142, 95% CI 1.018-1.281), lower postdialysis Na level (OR 0.724, 95% CI 0.556-0.942), and higher postdialysis Lac level (OR 2.465, 95% CI 1.126-5.397) were associated with PDF (p = 0.013, p = 0.024, p = 0.016, and p = 0.024, respectively). CONCLUSIONS The prevalence of PDF was high among our study participants. PDF incidence was correlated with the IDH occurrence and higher postdialysis Lac and lower postdialysis Na levels. The level of Lac was a significant influencing factor for the fatigue of patients. More attention should thus be paid to PDF.
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Effect of magnesium supplementation on lactate clearance in critically ill patients with severe sepsis: a randomized clinical trial.
Noormandi, A, Khalili, H, Mohammadi, M, Abdollahi, A
European journal of clinical pharmacology. 2020;(2):175-184
Abstract
OBJECTIVES In this study, changes in lactate clearance following magnesium supplementation were evaluated in critically ill patients with severe sepsis. METHODS Fifty-eight patients with severe sepsis were randomly assigned to receive either magnesium (n = 30) or placebo (n = 28). Patients in the magnesium group received intravenous magnesium sulfate to maintain serum magnesium level around 3 mg/dL for 3 days. The placebo group received the same volume of normal saline. Change in lactate clearance was considered primary outcome of the study. RESULTS Mean increase in the lactate clearance in the magnesium group was significantly higher than the placebo group on day 2 (27.53% vs. 23.79% respectively, p < 0.001) and day 3 (49.83% vs. 37.02% respectively, p < 0.001). Time to lactate clearance was also significantly shorter in the magnesium group than the placebo group (47.28 ± 20.59 vs. 61.20 ± 24.31 h respectively, p = 0.03). Sepsis-related mortality was not significantly different but median length of ICU stay was significantly shorter in the magnesium group than the placebo group (8 vs. 15 days respectively, p < 0.01). CONCLUSIONS Magnesium supplementation increased lactate clearance in critically ill patients with severe sepsis. Optimizing serum magnesium level near the upper limit of the normal range may improve severe sepsis outcomes.
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Long-term docosahexaenoic acid (DHA) supplementation in cystic fibrosis patients: a randomized, multi-center, double-blind, placebo-controlled trial.
López-Neyra, A, Suárez, L, Muñoz, M, de Blas, A, Ruiz de Valbuena, M, Garriga, M, Calvo, J, Ribes, C, Girón Moreno, R, Máiz, L, et al
Prostaglandins, leukotrienes, and essential fatty acids. 2020;:102186
Abstract
BACKGROUND Cystic fibrosis (CF) patients have an alteration in fatty acid (FA) metabolism, associated with increased omega-6 and low omega-3 FA. Previous studies on supplementation with omega-3 FA in CF had contradictory results, and to date there is no evidence to recommend routine use of omega-3 supplements in CF patients. We hypothesized that long-term supplementation with docosahexaenoic acid (DHA) will have beneficial effects in these patients, by reducing pulmonary, systemic and intestinal inflammation. METHODS This was a randomized, double-blind, parallel, placebo-controlled trial. CF patients (age >2 months) were randomized to receive a seaweed DHA oil solution (50 mg/Kg/day) or matching placebo for 48 weeks. Primary outcomes were pulmonary (interleukin [IL]-8), systemic (IL-8) and intestinal (calprotectin) inflammatory biomarkers. Secondary outcomes included other pulmonary (IL-1β, IL-6, neutrophil elastase, lactate and calprotectin) and systemic (serum-IL-1β, IL-6) inflammatory biomarkers, as well as clinical outcomes (FEV1, pulmonary exacerbations, antibiotic use, nutritional status and quality of life). RESULTS Ninety six CF patients, 44 female, age 14.6±11.9 years (48 DHA and 48 placebo) were included. At trial completion, there were no differences in all primary outcomes [serum-IL-8 (p=0.909), respiratory-IL-8 (p=0.384) or fecal calprotectin (p=0.948)], all secondary inflammatory biomarkers, or in any of the clinical outcomes evaluated. There were few adverse events, with similar incidence in both study groups. CONCLUSION In this study, long-term DHA supplementation in CF patients was safe, but did not offer any benefit on inflammatory biomarkers, or in clinical outcomes compared with placebo. (NCT01783613).
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Plasma Lactate as a Marker for Metabolic Health.
Broskey, NT, Zou, K, Dohm, GL, Houmard, JA
Exercise and sport sciences reviews. 2020;(3):119-124
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Abstract
Blood lactate concentrations traditionally have been used as an index of exercise intensity or clinical hyperlactatemia. However, more recent data suggest that fasting plasma lactate can also be indicative of the risk for subsequent metabolic disease. The hypothesis presented is that fasting blood lactate accumulation reflects impaired mitochondrial substrate use, which in turn influences metabolic disease risk.
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Ingestion of a moderate dose of alcohol enhances physical exercise-induced changes in blood lactate concentration.
Teixeira-Coelho, F, Santos, DFC, Santos, GA, Sousa, TF, Moreira, SR, Souza, MVC, Wanner, SP
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas. 2020;(4):e9200
Abstract
The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.
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Genome-scale modeling for Bacillus coagulans to understand the metabolic characteristics.
Chen, Y, Sun, Y, Liu, Z, Dong, F, Li, Y, Wang, Y
Biotechnology and bioengineering. 2020;(11):3545-3558
Abstract
Lactic acid is widely used in many industries, especially in the production of poly-lactic acid. Bacillus coagulans is a promising lactic acid producer in industrial fermentation due to its thermophilic property. In this study, we developed the first genome-scale metabolic model (GEM) of B. coagulans iBag597, together with an enzyme-constrained model ec-iBag597. We measured strain-specific biomass composition and integrated the data into a biomass equation. Then, we validated iBag597 against experimental data generated in this study, including amino acid requirements and carbon source utilization, showing that simulations were generally consistent with the experimental results. Subsequently, we carried out chemostats to investigate the effects of specific growth rate and culture pH on metabolism of B. coagulans. Meanwhile, we used iBag597 to estimate the intracellular metabolic fluxes for those conditions. The results showed that B. coagulans was capable of generating ATP via multiple pathways, and switched among them in response to various conditions. With ec-iBag597, we estimated the protein cost and protein efficiency for each ATP-producing pathway to investigate the switches. Our models pave the way for systems biology of B. coagulans, and our findings suggest that maintaining a proper growth rate and selecting an optimal pH are beneficial for lactate fermentation.