Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.785
Filtrar
1.
Pharmacol Rep ; 74(5): 1054-1068, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35939258

RESUMO

BACKGROUND: Luteolin, a naturally occurring flavonoid, is thought to have health-promoting properties as a part of human diet and has been reported to possess a wide range of pharmacological activities. Therefore, the present study was undertaken to evaluate the effect of luteolin pre-treatment on vascular dysfunctions in sepsis induced by caecal ligation and puncture (CLP) in the mouse model. METHODS: Mice were divided into four groups: sham, luteolin plus sham, CLP, and luteolin plus CLP. Luteolin was administered (0.2 mg/kg body weight) intraperitoneally one hour (h) before CLP surgery in mice. 20 ± 2 h post CLP surgery, the isolated thoracic aorta of mice was assessed for its vascular reactivity to noradrenaline (NA) and acetylcholine (ACh). To explore the underlying mechanism, aortic mRNA expressions of α1D adrenoceptors, eNOS and iNOS were investigated. RESULTS: In mice with CLP-induced sepsis luteolin pre-treatment markedly increased the survival time and attenuated serum lactate level. The CLP group manifested the reduced vascular reactivity to NA and this deficit was restored by luteolin pre-treatment. However, luteolin pre-treatment did not improve α1D adrenoceptors down-regulation observed in septic mice aorta. In the presence of 1400 W, the NA contractile response was significantly restored in CLP mice aortic tissue in comparison with the respective control of septic mice and further enhanced in the presence of luteolin. Luteolin reduced the iNOS mRNA expression and iNOS-derived nitrite production. Pre-treatment with luteolin restored the endothelial dysfunction in septic mice aorta by improving eNOS mRNA expression and enhanced eNOS-derived nitric oxide (NO) production in septic mice aorta and aortic iNOS gene expression and inducible NO production. CONCLUSION: The present study suggests that the vasoplegic state to NA in aorta was restored through the iNOS pathway and endothelial dysfunction was reversed via eNOS and NO production pathway.


Assuntos
Luteolina , Sepse , Animais , Humanos , Camundongos , Acetilcolina , Lactatos/sangue , Luteolina/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Nitritos/metabolismo , Norepinefrina/farmacologia , Punções , Receptores Adrenérgicos/metabolismo , RNA Mensageiro/metabolismo , Sepse/complicações , Sepse/tratamento farmacológico , Sepse/metabolismo
2.
Acta Orthop Traumatol Turc ; 56(4): 289-295, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35968622

RESUMO

OBJECTIVE: This study aimed to analyze the frequency of postoperative kidney injury, the related factors, and its effect on outcomes in major orthopedic surgery cases treated in the postanesthesia intensive care unit (PACU). METHODS: Major orthopedic surgery cases treated in the PACU were included in this study retrospectively. Demographic, operation, and anesthesia characteristics, CCI, ASA risk classes, preoperative biochemistry, and hemogram results of the patients were recorded. Postoperative serum creatinine level, urine output, renal replacement therapy requirement, and hemoglobin levels were recorded. The kidney damage of the patients was evaluated with RIFLE and AKIN criteria. Postoperative complications were recorded. RESULTS: The frequency of kidney injury in the early postoperative period was 7.1%. When only arthroplasty cases were taken, the frequency was 11%. It was determined that there was a correlation between preoperative ASA, CCI, BMI, K levels, lactate levels, and postoperative kidney damage (P <0.05). It was determined that the frequency and duration of inotropic use, the frequency and duration of noninvasive mechanical ventilation, and the duration of hospitalization increased in patients with postoperative kidney damage, and the frequency of pneumonia, wound infection, atelectasis, sepsis, arrhythmia, atrial fibrillation and mortality increased in the postoperative period (P <0.05). CONCLUSION: There is a need for further studies on the relationship between ASA, CCI, BMI, K, and lactate values and postoperative kidney damage. Postoperative kidney injury is associated with prolonged hospitalization and increased morbidity and mortality. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.


Assuntos
Injúria Renal Aguda , Procedimentos Ortopédicos , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Humanos , Lactatos/sangue , Lactatos/química , Procedimentos Ortopédicos/efeitos adversos , Estudos Retrospectivos , Fatores de Risco
3.
J Surg Res ; 277: 181-188, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35500513

RESUMO

INTRODUCTION: Gastrointestinal failure results in death in critically ill patients. This study aimed to explore the effect of dexmedetomidine (DEX) on intestinal barrier function and its mechanism in critically ill patients undergoing gastrointestinal surgery. METHODS: Patients undergoing gastrointestinal surgery were randomized into the DEX group (n = 21) or midazolam (MID) group (n = 21). Sufentanil was used for analgesia in both groups. In the DEX group, DEX was loaded (1 µg/kg) before sedation and infused (0.7 µg/kg/h) during sedation. In the MID group, MID was loaded (0.05 mg/kg) before sedation and infused (0.1 mg/kg/h) during sedation. The mean arterial pressure , heart rate , borborygmus resumption time , first defecation time, length of intensive care unit stay, and length of hospital stay were observed. The diamine oxidase (DAO), D-lactate , TNF-α, IL-6, and α7nAChR levels in plasma or hemocytes were detected before the start of sedation (0 h) and after sedation (24 h). RESULTS: No significant differences in age, sex, body mass index, Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were noted (P > 0.05). The mean arterial pressure between 0 h and 24 h showed no significant difference between the groups (P > 0.05), but the heart rate was significantly lower in the DEX group (P = 0.042). The borborygmus resumption time was significantly earlier in the DEX group (P = 0.034). The lengths of intensive care unit stay (P = 0.016) and hospital stay (P = 0.031) were significantly shorter in the DEX group. The TNF-α level in the DEX group was lower at 24 h than 0 h. The D-lactate level was significantly lower in the DEX group than the MID group at 24 h (P = 0.016). The expression of α7nAChR in the DEX group was significantly higher at 24 h than 0 h (P < 0.05). CONCLUSIONS: DEX maintained intestinal barrier integrity in patients undergoing gastrointestinal surgery through the cholinergic anti-inflammatory pathway.


Assuntos
Dexmedetomidina , Procedimentos Cirúrgicos do Sistema Digestório , Estado Terminal/terapia , Dexmedetomidina/uso terapêutico , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Humanos , Lactatos/sangue , Midazolam/uso terapêutico , Fator de Necrose Tumoral alfa/sangue , Receptor Nicotínico de Acetilcolina alfa7/sangue
4.
BMC Anesthesiol ; 21(1): 309, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34879822

RESUMO

BACKGROUND: Hyperlactatemia is associated with a poor prognosis in cardiac surgery patients. This study explored the impact of target blood pressure management during cardiopulmonary bypass (CPB) on blood lactate levels after cardiac surgery. METHODS: Adult patients undergoing cardiac valve surgery between 20/1/2020 and 30/6/2020 at Shanghai Chest Hospital were enrolled. The patients were randomized into a low mean arterial pressure (L-MAP) group (target MAP between 50 and 60 mmHg) or a high mean arterial pressure (H-MAP) group (target MAP between 70 and 80 mmHg), n = 20 for each. Norepinephrine was titrated only during CPB to maintain MAP at the target level. Blood lactate levels in the two groups were detected before the operation (T0), at the end of CPB (T1), at the end of the operation (T2), 1 h after the operation (T3), 6 h after the operation (T4) and 24 h after the operation (T5). The primary outcome was the blood lactate level at the end of the operation (T2). The secondary outcomes included the blood lactate level at T1, T3, T4, and T5 and the dose of epinephrine and dopamine within 24 h after the operation, time to extubation, length of stay in the ICU, incidence of readmission within 30 days, and mortality within 1 year. RESULTS: Forty patents were enrolled and analyzed in the study. The lactate level in the H-MAP group was significantly lower than that in the L-MAP group at the end of the operation (3.1 [IQR 2.1, 5.0] vs. 2.1 [IQR 1.7, 2.9], P = 0.008) and at the end of CPB and 1 hour after surgery. The dose of epinephrine within 24 h after the operation, time to extubation and length of stay in the ICU in the L-MAP group were significantly higher than those in the H-MAP group. CONCLUSIONS: Maintaining a relatively higher MAP during CPB deceased the blood lactate level at the end of surgery, reduced epinephrine consumption, and shortened the time to extubation and length of stay in the ICU after surgery. TRIAL REGISTRATION: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 8/1/2020 with the registration number ChiCTR2000028941 . It was conducted from 20/1/2020 to 30/6/2020 as a single, blinded trial in Shanghai Chest Hospital.


Assuntos
Pressão Sanguínea/fisiologia , Ponte Cardiopulmonar/métodos , Lactatos/sangue , Idoso , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
Medicine (Baltimore) ; 100(46): e27803, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34797307

RESUMO

OBJECTIVES: Fibromyalgia (FM) patients have an increased risk for glucose metabolism disturbances, and impaired glucose tolerance may be associated with symptom severity. Elevated levels of plasma lactate have been detected in FM patients. Both pyruvate and lactate are produced in glucose metabolism and reflect oxidative metabolism. The objective of our study was to analyse disturbances in glucose, pyruvate, or lactate metabolism in FM patients. METHODS: We measured plasma levels of glucose, pyruvate, and lactate during an oral glucose tolerance test in 40 non-diabetic, female FM patients and 30 age- and gender-matched healthy controls. RESULTS: FM patients showed a higher glycaemic response to the glucose load at 1 hour (F [1,68] = 10.4, P = .006) and 2 hours (F [1,68] = 7.80, P = .02), and higher glucose area under the curve (13.8 [SD 2.92] vs 11.6 [SD 2.31], P < .01), than healthy controls. Group differences were explained by higher body mass index and percentage of smokers among the FM patients. Pyruvate and lactate levels were similar in both groups. DISCUSSION: Impaired glucose regulation in FM patients is likely not due to FM itself, but to associated lifestyle factors. Our results highlight the importance of assessing the glucose regulation status and the lifestyle factors affecting glucose regulation in FM patients for prevention or early treatment of diabetes and associated complications. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03300635).


Assuntos
Fibromialgia/sangue , Glucose/metabolismo , Lactatos/sangue , Piruvatos/sangue , Adulto , Idoso , Glicemia , Estudos de Casos e Controles , Feminino , Fibromialgia/diagnóstico , Teste de Tolerância a Glucose , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade
6.
Cancer Med ; 10(23): 8475-8482, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34725958

RESUMO

BACKGROUND: The Multinational Association for Supportive Care in Cancer (MASCC) risk index has been utilized to determine the risk for poor clinical outcomes in patients with febrile neutropenia (FN) in an emergency center (EC). However, this index comprises subjective elements and elaborated metrics limiting its use in ECs. We sought to determine whether procalcitonin (PCT) level (biomarker of bacterial infection) with or without lactate level (marker of inadequate tissue perfusion) offers a potential alternative to MASSC score in predicting the outcomes of patients with FN presenting to an EC. METHODS: We retrospectively identified 550 cancer patients with FN who presented to our EC between April 2018, and April 2019, and had serum PCT and lactate levels measured. RESULTS: Compared with patients with PCT levels <0.25 ng/ml, those with levels ≥0.25 ng/ml had a significantly higher 14-day mortality rate (5.2% vs. 0.7%; p = 0.002), a higher bloodstream infection (BSI) rate, and a longer hospital length of stay (LOS). Logistic regression analysis showed that patients with PCT levels ≥0.25 ng/ml and lactate levels >2.2 mmol/L were more likely to be admitted and have an LOS >7 days, BSI, and 14-day mortality than patients with lower levels. PCT level was a significantly better predictor of BSI than MASSC score (p = 0.003) or lactate level (p < 0.0001). CONCLUSIONS: Procalcitonin level is superior to MASCC index in predicting BSI. The combination of PCT and lactate levels is a good predictor of BSI, hospital admission, and 14-day mortality and could be useful in identifying high-risk FN patients who require hospital admission.


Assuntos
Biomarcadores Tumorais/sangue , Neutropenia Febril/sangue , Neoplasias/sangue , Pró-Calcitonina/sangue , Adulto , Idoso , Feminino , Humanos , Lactatos/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade
7.
Am J Emerg Med ; 50: 120-125, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34343760

RESUMO

OBJECTIVE: Clinical research on drug intoxication is necessary for appropriate action in emergency departments (EDs). However, currently, there are no evident biomarkers for predicting adverse events (AEs) in patients with drug intoxication. We aimed to evaluate the prognostic value of serum lactate concentrations and lactate kinetics for AEs such as cardiogenic or respiratory failure in patients admitted to the ED with acute drug overdose. METHODS: We conducted a single-center retrospective study by reviewing the prospective suicide registry of patients visiting the ED. The primary outcome was composite AEs at any point during the ED visit or hospital stay. RESULTS: A total of 566 patients with acute drug overdose were enrolled in this study. Of these, 62 patients had AEs, whereas 363 patients did not, yielding an AE rate of 14.6%. The median 0 h lactate concentrations in the AE and non-AE groups were 2.7 [2.1-5.1] mmol/L and 2.1 [1.4-2.9] mmol/L, respectively (p < 0.001). The median 6 h lactate concentrations in the AE and non-AE groups were 2.0 [1.5-3.9] mmol/L and 1.3 [0.9-2.2] mmol/L, respectively (p < 0.001). The area under the curve of lactate at 0 h for predicting AEs was 0.705 (95% CI: 0.659-0.748). The optimal lactate cutoff point was 4.2 mmol/L (37.1% sensitivity, 92.8% specificity). Multivariable analysis using a stepwise backward method showed that the 0 h lactate concentration was associated with AEs in acute drug intoxication after adjusting for confounders (adjusted OR of 0 h lactate, 1.47; 95% CI, 1.23-1.77). However, the 6 h lactate concentrations, lactate clearance, and delta lactate levels did not predict the outcomes. CONCLUSION: Lactate concentrations and kinetics in patients admitted to the ED with an acute drug overdose exhibited limited prognostic utility in predicting AEs and should be interpreted with caution when considered for clinical decision-making.


Assuntos
Overdose de Drogas/sangue , Serviço Hospitalar de Emergência , Lactatos/sangue , Adulto , Feminino , Humanos , Lactatos/farmacocinética , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Sistema de Registros , Estudos Retrospectivos
8.
Eur J Appl Physiol ; 121(11): 3243-3255, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34435273

RESUMO

PURPOSE: Physical activity is associated with altered levels of circulating microRNAs (ci-miRNAs). Changes in miRNA expression have great potential to modulate biological pathways of skeletal muscle hypertrophy and metabolism. This study was designed to determine whether the profile of ci-miRNAs is altered after different approaches of endurance exercise. METHODS: Eighteen healthy volunteers (aged 24 ± 3 years) participated this three-arm, randomized-balanced crossover study. Each arm was a single bout of treadmill-based acute endurance exercise at (1) 100% of the individual anaerobic threshold (IANS), (2) at 80% of the IANS and (3) at 80% of the IANS with blood flow restriction (BFR). Load-associated outcomes (fatigue, feeling, heart rate, and exhaustion) as well as acute effects (circulating miRNA patterns and lactate) were determined. RESULTS: All training interventions increased the lactate concentration (LC) and heart rate (HR) (p < 0.001). The high-intensity intervention (HI) resulted in a higher LC than both lower intensity protocols (p < 0.001). The low-intensity blood flow restriction (LI-BFR) protocol led to a higher HR and higher LC than the low-intensity (LI) protocol without BFR (p = 0.037 and p = 0.003). The level of miR-142-5p and miR-197-3p were up-regulated in both interventions without BFR (p < 0.05). After LI exercise, the expression of miR-342-3p was up-regulated (p = 0.038). In LI-BFR, the level of miR-342-3p and miR-424-5p was confirmed to be up-regulated (p < 0.05). Three miRNAs and LC show a significant negative correlation (miR-99a-5p, p = 0.011, r = - 0.343/miR-199a-3p, p = 0.045, r = - 0.274/miR-125b-5p, p = 0.026, r = - 0.302). Two partial correlations (intervention partialized) showed a systematic impact of the type of exercise (LI-BFR vs. HI) (miR-99a-59: r = - 0.280/miR-199a-3p: r = - 0.293). CONCLUSION: MiRNA expression patterns differ according to type of activity. We concluded that not only the intensity of the exercise (LC) is decisive for the release of circulating miRNAs-as essential is the type of training and the oxygen supply.


Assuntos
Biomarcadores/sangue , Exercício Físico/fisiologia , MicroRNAs/sangue , Terapia de Restrição de Fluxo Sanguíneo , Estudos Cross-Over , Teste de Esforço , Feminino , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Lactatos/sangue , Masculino , Adulto Jovem
9.
Eur J Appl Physiol ; 121(11): 3201-3209, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34402986

RESUMO

PURPOSE: To investigate whether sub-technique transitions in the classical-style technique are associated with increased energy expenditure and/or metabolic stress among elite male cross-country skiers. METHODS: Fifteen elite male skiers completed three 10-min treadmill roller-skiing tests, each of which consisted of 5 min using the diagonal-stride technique (DS) and 5 min using the double-poling technique (DP), combined in three various modes all ensuring comparable mechanical workload, at an inclination of 2.5° and a speed of 13 km/h. In the first and third tests, the participants used 5 min continuous DS followed by 5 min continuous DP, or vice versa (no transition (NT) test), whereas in the second test, they made transitions between DS and DP every 6 s (repeated transition (RT) test). The last 3 min of each 5-min stage was used to calculate the mean values of oxygen uptake ([Formula: see text]), respiratory exchange ratio (RER), metabolic rate (MR), mechanical work rate (MWR), and gross efficiency (GE). In addition, the pre-post-difference in blood lactate concentration (Ladiff) was determined for each test. Paired-samples t tests were used to investigate differences between tests. RESULTS: There were no significant differences between NT and RT tests regarding V̇O2, MR, MWR, or GE. Conversely, significant differences were found in RER and Ladiff, where the NT test was associated with higher RER and Ladiff values. CONCLUSIONS: Roller skiing with repeated sub-technique transitions is not associated with an additional aerobic energy contribution; instead, the anaerobic energy contribution was lower compared to that under continuous use of DS and DP.


Assuntos
Desempenho Atlético/fisiologia , Metabolismo Energético/fisiologia , Consumo de Oxigênio/fisiologia , Esqui/fisiologia , Teste de Esforço , Humanos , Lactatos/sangue , Masculino , Adulto Jovem
10.
Mitochondrion ; 60: 21-26, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34273558

RESUMO

INTRODUCTION/BACKGROUND: Mitochondrial myopathy (MM) encompasses a clinical heterogenous group of patients that can be difficult to diagnose. The aim of this study was to investigate if changes in plasma lactate concentration during a 6-minute submaximal handgrip test (6MHGT) and a 20-minute post-exercise recovery period can be used as a diagnostic test for MM. METHODS: Twenty-nine patients with MM and nineteen healthy controls (HC) performed an intermittent handgrip exercise test at ½ Hz for 6 min at 50% of maximal voluntary contraction force. We calculated the area under the curve (AUC) of change in plasma lactate during exercise and recovery and compared AUC between groups (MM vs. HC, and between MM subgroups based on disease severity). RESULTS: The change in plasma lactate during exercise and recovery was similar in MM and HC (p = 0.65 and p = 0.57) and similar between MM subgroups (p ≥ 0.24). CONCLUSION: Plasma lactate measured during and after a submaximal 6MHGT cannot be used as a diagnostic variable for MM.


Assuntos
Exercício Físico/fisiologia , Força da Mão/fisiologia , Lactatos/sangue , Miopatias Mitocondriais/sangue , Miopatias Mitocondriais/diagnóstico , Adulto , Idoso , Área Sob a Curva , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Transfusion ; 61 Suppl 1: S167-S173, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269439

RESUMO

INTRODUCTION: We conducted a prospective observational study on 205 trauma patients at a level I trauma facility to test the hypothesis that a compensatory reserve measurement (CRM) would identify higher risk for progression to shock and/or need a life-saving interventions (LSIs) earlier than systolic blood pressure (SBP) and blood lactate (LAC). METHODS: A composite outcome metric included blood transfusion, procedural LSI, and mortality. Discrete measures assessed as abnormal (ab) were SBP <90 mmHg, CRM <60%, and LAC >2.0. A graded categorization of shock was defined as: no shock (normal [n] SBP [n-SBP], n-CRM, n-LAC); sub-clinical shock (ab-CRM, n-SBP, n-LAC); occult shock (n-SBP, ab-CRM, ab-LAC); or overt shock (ab-SBP, ab-CRM, ab-LAC). RESULTS: Three patients displayed overt shock, 53 displayed sub-clinical shock, and 149 displayed no shock. After incorporating lactate into the analysis, 86 patients demonstrated no shock, 25 were classified as sub-clinical shock, 91 were classified as occult shock, and 3 were characterized as overt shock. Each shock subcategory revealed a graded increase requiring LSI and transfusion. Initial CRM was associated with progression to shock (odds ratio = 0.97; p < .001) at an earlier time than SBP or LAC. CONCLUSIONS: Initial CRM uncovers a clinically relevant subset of patients who are not detected by SBP and LAC. Our results suggest CRM could be used to more expeditiously identify injured patients likely to deteriorate to shock, with requirements for blood transfusion or procedural LSI.


Assuntos
Transfusão de Sangue , Hemorragia/terapia , Choque Hemorrágico/terapia , Ferimentos e Lesões/terapia , Pressão Sanguínea , Feminino , Hemorragia/sangue , Hemorragia/diagnóstico , Hemorragia/fisiopatologia , Humanos , Lactatos/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Choque Hemorrágico/sangue , Choque Hemorrágico/diagnóstico , Choque Hemorrágico/fisiopatologia , Triagem , Ferimentos e Lesões/sangue , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/fisiopatologia
12.
Eur J Appl Physiol ; 121(11): 2981-2991, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34228222

RESUMO

PURPOSE: This study determined the effect of a single session of sprint interval training in hypoxia on muscle glycogen content among athletes. METHODS: Ten male college track and field sprinters (mean ± standard error of the mean: age, 21.1 ± 0.2 years; height, 177 ± 2 cm; body weight, 67 ± 2 kg) performed two exercise trials under either hypoxia [HYPO; fraction of inspired oxygen (FiO2), 14.5%] or normoxia (NOR: FiO2, 20.9%). The exercise consisted of 3 × 30 s maximal cycle sprints with 8-min rest periods between sets. Before and immediately after the exercise, the muscle glycogen content was measured using carbon magnetic resonance spectroscopy in vastus lateralis and vastus intermedius muscles. Moreover, power output, blood lactate concentrations, metabolic responses (respiratory oxygen uptake and carbon dioxide output), and muscle oxygenation were evaluated. RESULTS: Exercise significantly decreased muscle glycogen content in both trials (interaction, P = 0.03; main effect for time, P < 0.01). Relative changes in muscle glycogen content following exercise were significantly higher in the HYPO trial (- 43.5 ± 0.4%) than in the NOR trial (- 34.0 ± 0.3%; P < 0.01). The mean power output did not significantly differ between the two trials (P = 0.80). The blood lactate concentration after exercise was not significantly different between trials (P = 0.31). CONCLUSION: A single session of sprint interval training (3 × 30 s sprints) in hypoxia caused a greater decrease in muscle glycogen content compared with the same exercise under normoxia without interfering with the power output.


Assuntos
Metabolismo Energético/fisiologia , Glicogênio/metabolismo , Treinamento Intervalado de Alta Intensidade , Hipóxia/metabolismo , Músculo Esquelético/metabolismo , Dióxido de Carbono/metabolismo , Teste de Esforço , Humanos , Lactatos/sangue , Masculino , Consumo de Oxigênio/fisiologia , Adulto Jovem
13.
Eur J Appl Physiol ; 121(8): 2295-2304, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33974126

RESUMO

PURPOSE: Interval exercise allows very high-power outputs to be maintained, a key for stimulating training adaptations. The main purpose of this study was to develop a sprint interval protocol that stimulated both anaerobic and aerobic systems while maximizing power output and minimizing fatigue. The secondary goal was to investigate the influence of inter-sprint recovery duration. METHODS: Sixteen (8 females) participants (age: 23.5 ± 3.4 years, peak oxygen consumption (VO2peak): 45.6 ± 9.2 ml kg-1 min-1) took part in this study. The exercise protocol involved 30 bouts of 4 s maximal cycling sprints using an 'Inertial Load Ergometer'. Recovery durations between sprints of 15, 30 and 45 s were studied in three trials. RESULTS: Peak power output (PPO) was maintained while taking 45 and 30 s of recovery, although it was 9% higher (p < 0.05) during 45 vs. 30 s. PPO with 15 s recovery declined 18% (p < 0.05) and then stabilized as did oxygen consumption (72±2% VO2peak) at a level that might reflect the peak rate of ATP-PC resynthesis from oxidative metabolism. The 15-, 30-, and 45 s trials elicited 72, 56, and 49% VO2peak and 86, 80, and 75% of maximal heart rate (all p<0.001). Perceived exertion increased with shorter recovery periods but remained at 12.6-14.7 and never became 'very hard'. CONCLUSION: The present study describes the use of an inertial-load ergometer to accommodate repeated 4 s maximal cycling sprints that elicit 72% VO2peak when the recovery period is 15 s. However, a recovery duration of 15 s was insufficient for the maintenance of power generation. TRIAL REGISTRATION NUMBER AND DATE: NCT04448925, 26 Jun 2020; retrospectively registered to clinicaltrials.gov.


Assuntos
Adaptação Fisiológica/fisiologia , Ciclismo/fisiologia , Esforço Físico/fisiologia , Aceleração , Estudos Cross-Over , Feminino , Frequência Cardíaca/fisiologia , Humanos , Lactatos/sangue , Masculino , Consumo de Oxigênio/fisiologia , Troca Gasosa Pulmonar/fisiologia , Adulto Jovem
14.
Transfusion ; 61(7): 2082-2089, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33955577

RESUMO

BACKGROUND: Massive transfusions are associated with a high mortality rate, but there is little evidence indicating when such efforts are futile. The purpose of this study was to identify clinical variables that could be used as futility indicators in massively transfused patients. METHODS: We retrospectively analyzed 138 adult surgical patients at our institution receiving a massive transfusion (2016-2019). Peak lactate and nadir pH within 24 h of massive transfusion initiation, along with other clinical variables, were assessed as predictors of the primary outcome, in-hospital mortality. RESULTS: The overall rate of in-hospital mortality among our patient population was 52.9% (n = 73). Increasing lactate and decreasing pH were associated with greater mortality among massively transfused patients. Mortality rates were ~2-fold higher for patients in the highest lactate category (≥10.0 mmol/L: 25 of 37; 67.6%) compared to the lowest category (0.0-4.9 mmol/L: 17 of 48; 35.4%) (p = .005), and ~2.5-fold higher for patients in the lowest pH category (<7.00: 8 of 9; 88.9%) compared to the highest category (≥7.40: 8 of 23; 34.7%) (p = .016). Increasing age was also associated with higher mortality (≥65 years: 24 of 33; 72.7%) when compared to younger patients (18-64 years: 49 of 105; 46.7%) (p = .010). CONCLUSIONS: Peak lactate ≥10.0 mmol/L, nadir pH <7.00, and age ≥65 years were significantly associated with higher rates of in-hospital mortality among massively transfused patients. Incorporating these clinical parameters into a futility index for massive transfusions will be useful in situations where blood products are scarce and/or mortality may be unavoidable.


Assuntos
Transfusão de Sangue , Mortalidade Hospitalar , Concentração de Íons de Hidrogênio , Lactatos/sangue , Futilidade Médica , Adulto , Fatores Etários , Idoso , Área Sob a Curva , Biomarcadores/sangue , Feminino , Departamentos Hospitalares , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Prognóstico , Curva ROC , Estudos Retrospectivos , Procedimentos Cirúrgicos Operatórios , Adulto Jovem
15.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946157

RESUMO

The metabolic ratios lactate/pyruvate and ß-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, ß-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency's Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and ß-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.


Assuntos
Ácido 3-Hidroxibutírico/metabolismo , Acetoacetatos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Lactatos/metabolismo , Piruvatos/metabolismo , Ácido 3-Hidroxibutírico/análise , Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/análise , Acetoacetatos/sangue , Animais , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Células Hep G2 , Humanos , Lactatos/análise , Lactatos/sangue , Limite de Detecção , Fígado/química , Fígado/metabolismo , Oxirredução , Piruvatos/análise , Piruvatos/sangue , Ratos Wistar
16.
Eur J Appl Physiol ; 121(8): 2229-2241, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33893836

RESUMO

PURPOSE: This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. METHODS: Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. RESULTS: No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L-1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ([Formula: see text]O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). CONCLUSION: In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher [Formula: see text]O2peak values when using DS compared to DP.


Assuntos
Esqui/fisiologia , Aceleração , Adolescente , Desempenho Atlético/fisiologia , Metabolismo Energético , Feminino , Frequência Cardíaca/fisiologia , Humanos , Lactatos/sangue , Masculino , Consumo de Oxigênio/fisiologia
17.
Eur J Appl Physiol ; 121(7): 2061-2076, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33811558

RESUMO

PURPOSE: This study investigated the effect of performing hypoxic exercise at the same heart rate (HR) or work rate (WR) as normoxic exercise on post-exercise autonomic and cardiovascular responses. METHODS: Thirteen men performed three interval-type exercise sessions (5 × 5-min; 1-min recovery): normoxic exercise at 80% of the WR at the first ventilatory threshold (N), hypoxic exercise (FiO2 = 14.2%) at the same WR as N (H-WR) and hypoxic exercise at the same HR as N (H-HR). Autonomic and cardiovascular assessments were conducted before and after exercise, both at rest and during active squat-stand manoeuvres (SS). RESULTS: Compared to N, H-WR elicited a higher HR response (≈ 83% vs ≈ 75%HRmax, p < 0.001) and H-HR a reduced exercise WR (- 21.1 ± 9.3%, p < 0.001). Cardiac parasympathetic indices were reduced 15 min after exercise and recovered within 60 min in N and H-HR, but not after H-WR (p < 0.05). H-WR altered cardiac baroreflex sensitivity (cBRS) both at rest and during SS (specifically in the control of blood pressure fall during standing phases) in the first 60 min after the exercise bout (p < 0.05). Post-exercise hypotension (PEH) did not occur in H-HR (p > 0.05) but lasted longer in H-WR than in N (p < 0.05). CONCLUSIONS: Moderate HR-matched hypoxic exercise mimicked post-exercise autonomic responses of normoxic exercise without resulting in significant PEH. This may relate to the reduced WR and the limited associated mechanical/metabolic strain. Conversely, WR-matched hypoxic exercise impacted upon post-exercise autonomic and cardiovascular responses, delaying cardiac autonomic recovery, temporarily decreasing cBRS and evoking prolonged PEH.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Exercício Físico/fisiologia , Hipóxia/fisiopatologia , Adulto , Biomarcadores/sangue , Frequência Cardíaca/fisiologia , Monitorização Hemodinâmica , Humanos , Lactatos/sangue , Masculino
18.
Eur J Appl Physiol ; 121(7): 2091-2100, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33835198

RESUMO

PURPOSE: To investigate sports compression garment (CG)-induced recovery hemodynamics and their potential impact on subsequent cycling performance. METHODS: In a randomized crossover design, 13 physically active men (20.9 ± 1.4 years; 65.9 ± 7.8 kg; 173.3 ± 4.8 cm; peak power output 254.2 ± 27.2 W) underwent 2 experimental trials. During each experimental trial, the subjects performed 20-min fatiguing preload cycling followed by 60-min passive recovery wearing either a sports CG (28.6 ± 9.4 mmHg) or gymnastic pants (CON). A 5-min all-out cycling performance test was subsequently conducted and power output and cadence were recorded. Cardiac output (CO) and stroke volume (SV) were measured using Doppler ultrasound (USCOM®). Heart rate (HR), blood lactate [BLa-], ratings of perceived exertion (RPE), leg muscle soreness (LMS), mean arterial pressure (MAP) and systemic vascular resistance (SVR) were monitored at 5, 15, 30, 45, 60 min during passive recovery. RESULTS: During the subsequent 5-min all-out cycling performance test, power output (215.2 ± 24.0 vs. 210.8 ± 21.5 W, CG vs. CON) and cadence (72.5 ± 3.8 vs. 71.2 ± 4.8 rpm, CG vs. CON) were higher in CG than CON (P < 0.05). SV was higher at 15, 30 and 45 min (P < 0.05), CO was higher at 5 and 45 min (P < 0.05), HR was lower at 15 and 30 min (P < 0.05) and [BLa-] was lower at 5 and 15 min (P < 0.05) during passive recovery, while LMS was lower at all time-points (P < 0.05) compared with CON. CONCLUSION: Sports CG improves subsequent cycling performance by enhancing hemodynamic responses and attenuating perceived muscle soreness during passive recovery in physically active men.


Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Meias de Compressão , Débito Cardíaco/fisiologia , Estudos Cross-Over , Frequência Cardíaca/fisiologia , Humanos , Lactatos/sangue , Masculino , Mialgia/prevenção & controle , Esforço Físico/fisiologia , Volume Sistólico/fisiologia , Ultrassonografia Doppler , Resistência Vascular , Adulto Jovem
19.
Am J Case Rep ; 22: e930175, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33867519

RESUMO

BACKGROUND The normalization of serum lactate levels in a patient with non-syndromic mitochondrial disorder due to the m.3243A>G mitochondrial DNA (mtDNA) variant has not been previously reported. CASE REPORT A 57-year-old woman was diagnosed with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) due to the m.3243A>G variant, with low heteroplasmy rates (31%), at age 50. The initial manifestations were short stature, migraine, and diabetes. With progression of the disease, multisystem involvement developed, affecting the brain (stroke-like episode, mild cognitive impairment), eyes (pigmentary retinopathy), ears and the vestibular system (impaired hearing, tinnitus, imbalance, drop attacks, vertigo), intestines (constipation, distended abdomen, gastro-esophageal reflux, gastroparesis), and the muscles (muscle weakness). The gastrointestinal involvement was most prominent and most significantly lowered the patient's quality of life. The diabetes was well controlled with an insulin pump. Recurrent, acute deteriorations responded favorably to L-arginine. Owing to lifestyle and diet changes 2 years after diagnosis (start of art classes, increase in spin biking to 22.5 km 3 times per week, travel to Hawaii, adherence to low-carbohydrate high-protein diet), the patient managed to lower elevated serum lactate levels to largely normal values. CONCLUSIONS Gastrointestinal compromise may be the prominent manifestation of the m.3243A>G variant, lifestyle and diet changes may lower serum lactate in m.3243A>G carriers, and low heteroplasmy rates of the m.3243A>G variant in scarcely affected tissues do not exclude pathogenicity.


Assuntos
DNA Mitocondrial/genética , Lactatos/sangue , Estilo de Vida , Síndrome MELAS/sangue , Síndrome MELAS/terapia , Doenças Mitocondriais/genética , Feminino , Heteroplasmia/genética , Humanos , Síndrome MELAS/diagnóstico , Pessoa de Meia-Idade , Doenças Mitocondriais/diagnóstico , Mutação , Qualidade de Vida
20.
Neurol Res ; 43(7): 582-590, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33657991

RESUMO

Objective: To study the serum lactate level in MS and to explore its correlation with the progression and disability in multiple sclerosis (MS), and the important role of mitochondrial dysfunction in the pathogenesis of MS.Methods: This case-control study included 80 participants, involved 50 MS patients and 30 normal healthy controls. Detailed history taking, complete neurological examination, and clinical evaluation of the disability using the Expanded Disability Status Scale (EDSS) were done for all patients. Level of serum lactate was measured in both groups and was correlated with EDSS, MS subtypes, MRI brain, and MRS findings.Results: Serum lactate in MS patients was about three and half times higher than serum lactate levels of healthy controls (22.87 ± 5.92 mg/dl versus 6.39 ± 0.9 6.39 ± 0.91, p < 0.001). Importantly, serum lactate values were increased in MS cases with a progressive course compared with MS cases with RR course. Also, there were linearly correlations linking serum lactate levels and the duration of MS (r = 0.342, P = 0.015), relapses numbers (r = 0.335, P = 0.022), and EDSS (r = 0.483, P < 0.001). Also, there were strong positive correlations between serum lactate and Lipid/Lactate (r = 0.461, P = 0.001), periventricular lesion (r = 0.453, P = 0.005), and moderate positive correlations between serum lactate and juxtacortical lesion (r = 0.351, P = 0.02), and infratentorial lesion (r = 0.355, P = 0.02).Conclusion: Measurement of serum lactate may be helpful in MS and this supports the hypothesis of the critical role of mitochondrial dysfunction and axonal damage in MS.Registration of Clinical Trial Research: ClinicalTrials.gov ID: NCT04210960.


Assuntos
Biomarcadores/sangue , Lactatos/sangue , Mitocôndrias/metabolismo , Esclerose Múltipla/etiologia , Neuroimagem , Adolescente , Adulto , Axônios/patologia , Avaliação da Deficiência , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/patologia , Esclerose Múltipla/patologia , Neuroimagem/métodos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...