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1.
Artigo em Inglês | MEDLINE | ID: mdl-33153145

RESUMO

Wearing face masks is recommended for the prevention of contracting or exposing others to cardiorespiratory infections, such as COVID-19. Controversy exists on whether wearing face masks during vigorous exercise affects performance. We used a randomized, counterbalanced cross-over design to evaluate the effects of wearing a surgical mask, a cloth mask, or no mask in 14 participants (7 men and 7 women; 28.2 ± 8.7 y) during a cycle ergometry test to exhaustion. Arterial oxygen saturation (pulse oximetry) and tissue oxygenation index (indicator of hemoglobin saturation/desaturation) at vastus lateralis (near-infrared spectroscopy) were assessed throughout the exercise tests. Wearing face masks had no effect on performance (time to exhaustion (mean ± SD): no mask 622 ± 141 s, surgical mask 657 ± 158 s, cloth mask 637 ± 153 s (p = 0.20); peak power: no mask 234 ± 56 W, surgical mask 241 ± 57 W, cloth mask 241 ± 51 W (p = 0.49)). When expressed relative to peak exercise performance, no differences were evident between wearing or not wearing a mask for arterial oxygen saturation, tissue oxygenation index, rating of perceived exertion, or heart rate at any time during the exercise tests. Wearing a face mask during vigorous exercise had no discernable detrimental effect on blood or muscle oxygenation, and exercise performance in young, healthy participants (ClinicalTrials.gov, NCT04557605).


Assuntos
Infecções por Coronavirus/prevenção & controle , Exercício Físico , Máscaras/classificação , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Adulto , Betacoronavirus , Teste de Esforço , Feminino , Humanos , Masculino , Oximetria , Consumo de Oxigênio , Adulto Jovem
2.
Chem Biol Interact ; 331: 109272, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33010220

RESUMO

A cellular model of cardiomyocytes (H9c2 cell line) and mitochondria isolated from mouse liver were used to understand the drug action of BPDZ490 and BPDZ711, two benzopyran analogues of the reference potassium channel opener cromakalim, on mitochondrial respiratory parameters and swelling, by comparing their effects with those of the parent compound cromakalim. For these three compounds, the oxygen consumption rate (OCR) was determined by high-resolution respirometry (HRR) and their impact on adenosine triphosphate (ATP) production and calcium-induced mitochondrial swelling was investigated. Cromakalim did not modify neither the OCR of H9c2 cells and the ATP production nor the Ca-induced swelling. By contrast, the cromakalim analogue BPDZ490 (1) induced a strong increase of OCR, while the other benzopyran analogue BPDZ711 (2) caused a marked slowdown. For both compounds, 1 displayed a biphasic behavior while 2 still showed an inhibitory effect. Both compounds 1 and 2 were also found to decrease the ATP synthesis, with pronounced effect for 2, while cromakalim remained without effect. Overall, these results indicate that cromakalim, as parent molecule, does not induce per se any direct effect on mitochondrial respiratory function neither on whole cells nor on isolated mitochondria whereas both benzopyran analogues 1 and 2 display totally opposite behavior profiles, suggesting that compound 1, by increasing the maximal respiration capacity, might behave as a mild uncoupling agent and compound 2 is taken as an inhibitor of the mitochondrial electron-transfer chain.


Assuntos
Cromakalim/análogos & derivados , Mitocôndrias/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/farmacologia , Linhagem Celular , Cromakalim/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Canais de Potássio/agonistas , Canais de Potássio/metabolismo , Taxa Respiratória/efeitos dos fármacos
3.
Nat Commun ; 11(1): 4627, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009389

RESUMO

Animals have evolved responses to low oxygen conditions to ensure their survival. Here, we have identified the C. elegans zinc finger transcription factor PQM-1 as a regulator of the hypoxic stress response. PQM-1 is required for the longevity of insulin signaling mutants, but surprisingly, loss of PQM-1 increases survival under hypoxic conditions. PQM-1 functions as a metabolic regulator by controlling oxygen consumption rates, suppressing hypoxic glycogen levels, and inhibiting the expression of the sorbitol dehydrogenase-1 SODH-1, a crucial sugar metabolism enzyme. PQM-1 promotes hypoxic fat metabolism by maintaining the expression of the stearoyl-CoA desaturase FAT-7, an oxygen consuming, rate-limiting enzyme in fatty acid biosynthesis. PQM-1 activity positively regulates fat transport to developing oocytes through vitellogenins under hypoxic conditions, thereby increasing survival rates of arrested progeny during hypoxia. Thus, while pqm-1 mutants increase survival of mothers, ultimately this loss is detrimental to progeny survival. Our data support a model in which PQM-1 controls a trade-off between lipid metabolic activity in the mother and her progeny to promote the survival of the species under hypoxic conditions.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Hipóxia/metabolismo , Metabolismo dos Lipídeos , Transativadores/metabolismo , Animais , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica , Glicogênio/metabolismo , Insulina/metabolismo , Larva/metabolismo , Mutação/genética , Consumo de Oxigênio , Transdução de Sinais , Estresse Fisiológico , Análise de Sobrevida , Transativadores/genética , Transcrição Genética , Vitelogeninas/metabolismo
4.
Nat Commun ; 11(1): 4936, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024098

RESUMO

Wearable exercise trackers provide data that encode information on individual running performance. These data hold great potential for enhancing our understanding of the complex interplay between training and performance. Here we demonstrate feasibility of this idea by applying a previously validated mathematical model to real-world running activities of  ≈ 14,000 individuals with ≈ 1.6 million exercise sessions containing duration and distance, with a total distance of ≈ 20 million km. Our model depends on two performance parameters: an aerobic power index and an endurance index. Inclusion of endurance, which describes the decline in sustainable power over duration, offers novel insights into performance: a highly accurate race time prediction and the identification of key parameters such as the lactate threshold, commonly used in exercise physiology. Correlations between performance indices and training volume and intensity are quantified, pointing to an optimal training. Our findings hint at new ways to quantify and predict athletic performance under real-world conditions.


Assuntos
Modelos Teóricos , Corrida/fisiologia , Atletas , Big Data , Exercício Físico/fisiologia , Humanos , Ácido Láctico/metabolismo , Consumo de Oxigênio , Resistência Física/fisiologia , Dispositivos Eletrônicos Vestíveis
5.
Cent Eur J Public Health ; 28 Suppl: S53-S56, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33069182

RESUMO

OBJECTIVES: Low cardiorespiratory fitness (CRF) is related to higher risk of cardiovascular diseases, increase in all-cause mortality and higher risk of different tumors. The reverse is also true; improvement in CRF is related to decrease in mortality. Cardiopulmonary exercise testing (CPET) is a standard and also the most precise test for determination of CRF - the best possibility is the maximal test measuring different parameters including maximal oxygen consumption. Healthcare professionals throughout the developed world have markedly high rates of sickness absence, burnout, and distress compared to other sectors and this leads to higher risk factors. The study aimed to assess CRF in a group of nurses in a big hospital and compare it with population norms and available published results. METHODS: Nurses over 50 years of age working in one faculty hospital were gradually included in the study from the beginning of 2018. These nurses work in physically demanding positions. A CPET was carried out following the Bruce protocol. RESULTS: 90 nurses (84 females and 6 males), mean age 55.7 years, were evaluated by CPET. The resting blood pressure was within the norm in 58 persons (64.44%), maximal oxygen consumption in 61 persons (67.8%), W/kg in 25 persons (46.2%). We detected a hypertension reaction in 28 persons (31.1%), some types of arrhythmia in 17 persons (18.9%) and signs of ischaemia in 8 persons (8.9%). The result of CPET led to further examination in 42 persons (46.6%). Detailed examination resulted in change of medication in 21 nurses (23.3%). New diseases were diagnosed in 15 nurses (hypertension, atrial fibrillation, mitral valve prolapse indicated for cardiac surgery, coronary artery stenosis, and lipid disorders). CONCLUSIONS: It was concluded that the usage of CPET during the regular medical check-ups significantly increases detection of hidden diseases and thus improves the care for nurses.


Assuntos
Aptidão Cardiorrespiratória , Doenças Cardiovasculares , Teste de Esforço , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros , Estresse Ocupacional , Consumo de Oxigênio
6.
Cochrane Database Syst Rev ; 10: CD013400, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33112424

RESUMO

BACKGROUND: Congenital heart disease (ConHD) affects approximately 1% of all live births. People with ConHD are living longer due to improved medical intervention and are at risk of developing non-communicable diseases. Cardiorespiratory fitness (CRF) is reduced in people with ConHD, who deteriorate faster compared to healthy people. CRF is known to be prognostic of future mortality and morbidity: it is therefore important to assess the evidence base on physical activity interventions in this population to inform decision making. OBJECTIVES: To assess the effectiveness and safety of all types of physical activity interventions versus standard care in individuals with congenital heart disease. SEARCH METHODS: We undertook a systematic search on 23 September 2019 of the following databases: CENTRAL, MEDLINE, Embase, CINAHL, AMED, BIOSIS Citation Index, Web of Science Core Collection, LILACS and DARE. We also searched ClinicalTrials.gov and we reviewed the reference lists of relevant systematic reviews. SELECTION CRITERIA: We included randomised controlled trials (RCT) that compared any type of physical activity intervention against a 'no physical activity' (usual care) control. We included all individuals with a diagnosis of congenital heart disease, regardless of age or previous medical interventions.  DATA COLLECTION AND ANALYSIS: Two review authors (CAW and CW) independently screened all the identified references for inclusion. We retrieved and read all full papers; and we contacted study authors if we needed any further information. The same two independent reviewers who extracted the data then processed the included papers, assessed their risk of bias using RoB 2 and assessed the certainty of the evidence using the GRADE approach. The primary outcomes were: maximal cardiorespiratory fitness (CRF) assessed by peak oxygen consumption; health-related quality of life (HRQoL) determined by a validated questionnaire; and device-worn 'objective' measures of physical activity. MAIN RESULTS: We included 15 RCTs with 924 participants in the review. The median intervention length/follow-up length was 12 weeks (12 to 26 interquartile range (IQR)). There were five RCTs of children and adolescents (n = 500) and 10 adult RCTs (n = 424). We identified three types of intervention: physical activity promotion; exercise training; and inspiratory muscle training. We assessed the risk of bias of results for CRF as either being of some concern (n = 12) or at a high risk of bias (n = 2), due to a failure to blind intervention staff. One study did not report this outcome. Using the GRADE method, we assessed the certainty of evidence as moderate to very low across measured outcomes. When we pooled all types of interventions (physical activity promotion, exercise training and inspiratory muscle training), compared to a 'no exercise' control CRF may slightly increase, with a mean difference (MD) of 1.89 mL/kg-1/min-1 (95% CI -0.22 to 3.99; n = 732; moderate-certainty evidence). The evidence is very uncertain about the effect of physical activity and exercise interventions on HRQoL. There was a standardised mean difference (SMD) of 0.76 (95% CI -0.13 to 1.65; n = 163; very low certainty evidence) in HRQoL. However, we could pool only three studies in a meta-analysis, due to different ways of reporting. Only one study out of eight showed a positive effect on HRQoL. There may be a small improvement in mean daily physical activity (PA) (SMD 0.38, 95% CI -0.15 to 0.92; n = 328; low-certainty evidence), which equates to approximately an additional 10 minutes of physical activity daily (95% CI -2.50 to 22.20). Physical activity and exercise interventions likely result in an increase in submaximal cardiorespiratory fitness (MD 2.05, 95% CI 0.05 to 4.05; n = 179; moderate-certainty evidence). Physical activity and exercise interventions likely increase muscular strength (MD 17.13, 95% CI 3.45 to 30.81; n = 18; moderate-certainty evidence). Eleven studies (n = 501) reported on the outcome of adverse events (73% of total studies). Of the 11 studies, six studies reported zero adverse events. Five studies reported a total of 11 adverse events; 36% of adverse events were cardiac related (n = 4); there were, however, no serious adverse events related to the interventions or reported fatalities (moderate-certainty evidence). No studies reported hospital admissions. AUTHORS' CONCLUSIONS: This review summarises the latest evidence on CRF, HRQoL and PA. Although there were only small improvements in CRF and PA, and small to no improvements in HRQoL, there were no reported serious adverse events related to the interventions. Although these data are promising, there is currently insufficient evidence to definitively determine the impact of physical activity interventions in ConHD. Further high-quality randomised controlled trials are therefore needed, utilising a longer duration of follow-up.


Assuntos
Exercícios Respiratórios , Aptidão Cardiorrespiratória/fisiologia , Exercício Físico/fisiologia , Cardiopatias Congênitas/reabilitação , Adolescente , Adulto , Viés , Criança , Feminino , Humanos , Masculino , Força Muscular , Consumo de Oxigênio/fisiologia , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Chem Biol Interact ; 331: 109249, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32980322

RESUMO

Oxidative stress provides a major contribution to the pathogenesis of glaucoma and may induce retinal ganglion cell (RGC) damage. Transforming growth factor ß (TGF-ß) has appeared as a neuroprotective protein in various indignities. However, the TGF-ß mechanism of protective effects against oxidative stress damage in RGCs still undetermined. In our research, we investigated the regulatory mechanisms and potential effects of TGF-ß1 & TGF-ß2 in hydrogen peroxide (H2O2)-stimulated oxidative stress of RGCs in vitro. By a series of cell functional qualitative analysis, such as MTT cell viability assay, wound healing ability assay, apoptosis assay, intracellular ROS detection, immunoblot analysis, intracellular GSH content, and high-resolution respirometry, we illustrated the cell state in oxidative stress-induced injury. Results of protein expression showed that TGF-ß1 & TGF-ß2 was upregulated in RGCs after H2O2 stimulation. Cell functional assays resulted that knockdown of TGF-ß1 & TGF-ß2 reduced survival rate whereas enhanced apoptosis and accumulation of reactive oxygen species (ROS). Especially TGF-ß1 upregulation promoted the protein expression of aldehyde dehydrogenase 3A1 (ALDH3A1) and increased the activity of antioxidant and neuroprotection pathways. Additionally, TGF-ß1 & TGF-ß2 on antioxidant signaling was related to activation of heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor (Nrf2), which are stress-response proteins. ROS accumulation followed by the accumulation of hypoxia-inducible factor (HIF-1α) caused mitochondrial damage and led to neurodegeneration. In summary, our results demonstrated that TGF-ß1 preserves RGCs from free radicals-mediated injury by upregulating the activation of Nrf2 expression and HO-1 signaling balance HIF-1α upregulation, implying a prospective role of TGF-ß1 in retinal neuroprotection-related therapies.


Assuntos
Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Acetilcisteína/farmacologia , Aldeído Desidrogenase/metabolismo , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glutationa/metabolismo , Heme Oxigenase-1/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/metabolismo , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologia
8.
J Sports Med Phys Fitness ; 60(8): 1057-1064, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32955831

RESUMO

BACKGROUND: Rock climbers are characterized by enhanced forearm fatigue resistance. This study compared the forearm isometric force of rock climbers (RC), strength-matched power lifters (PL) and aerobically trained (AT) athletes to determine the contribution of muscle oxygen desaturation during ischemia. METHODS: Aerobically trained athletes (N.=6, 23±1 years, 77±1 kg), power lifters (N.=7, 24±1 years, 80±3 kg) and rock climbers (N.=8, 25±2 years, 74±2 kg) took part in a controlled forearm ischemic occlusion (5 min) assessment using near infrared spectroscopy. In addition, three fatigue protocols were completed: protocol 1, sustained maximal voluntary contraction (MVC) until exhaustion; protocol 2, sustained 40% MVC for 3 mins duration; protocol 3, an intermittent 40% MVC (5-s contraction, 5-s recovery) for a duration of 3 mins. Forearm contractile fatigue was quantified as the reduction in MVC. RESULTS: MVC was equivalent between groups (P>0.05). Sustained MVC force (time to decline 50% MVC) was longer in the RC versus AT (AT: 35±5, PL: 46±6, RC: 54±4 s, P<0.05) and both AT and PL for sustained 40% MVC (AT: 56±9, RT: 62±8, RC: 87±7 s, P<0.05). Reduction in MVC was less in RC post intermittent 40% contractions (P<0.05). Oxygen desaturation half-time was longer in the RC versus AT (AT: 65±9, RT: 86±7, RC: 99±7 s, P<0.05) and this was associated with time to 50% MVC (P<0.05, r2=0.53) and time to 40% MVC task failure (P<0.05, r2=0.32). CONCLUSIONS: Rock climbers' enhanced isometric fatigue-resistance and ability to maintain MVC was associated with a lower oxygen consumption of the forearm flexors during the ischemic state. This suggests a training adaptation involving intracellular oxygen consumption.


Assuntos
Antebraço/fisiologia , Montanhismo/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Adaptação Fisiológica , Adulto , Dedos/fisiologia , Antebraço/irrigação sanguínea , Antebraço/diagnóstico por imagem , Humanos , Contração Isométrica/fisiologia , Masculino , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/diagnóstico por imagem , Consumo de Oxigênio , Condicionamento Físico Humano/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Levantamento de Peso/fisiologia , Adulto Jovem
9.
J Sports Med Phys Fitness ; 60(8): 1110-1117, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32955837

RESUMO

BACKGROUND: Vinyasa yoga has been recently promoted as one of the most popular mindful exercises to improve overall health, including body weight management. The purpose of this study was to determine the metabolic response of 24 moderately trained individuals during a 90-min group Vinyasa yoga routine. METHODS: Heart rate (HR) time course of 12 males and 12 females (age: 39±7.33 years) was recorded during two group Vinyasa yoga sessions consisted of four sections (warm-up, high-intensity Surya Namaskar (HSN), no Surya Namaskar postures, and cool-down). Maximal oxygen uptake (V̇O2peak) and maximum HR had been estimated earlier after a maximal treadmill test. V̇O2 during Vinyasa yoga sessions was estimated from individual regression equations using the relationship of V̇O2 and HR values derived from V̇O2peak test, while the metabolic rate (kcal/min) was calculated from the relationship of HR and kcal/min. Total session energy consumption was the average value of the two yoga sessions. RESULTS: The 2 (gender) × 4 (sections) mixed ANOVA revealed no significant interaction between the two factors (P=0.101) for the mean metabolic rate (7.1±2.6 kcal/min). Mean metabolic rate thought was higher (P=0.015) in males compared to females at each section. Also, significant differences were found among the four Vinyasa yoga sections (P<0.001) in the rate of energy expenditure, with HSN presenting the highest mean values (P<0.05). CONCLUSIONS: It seems that systematic participation in Vinyasa yoga may effectively improve cardiorespiratory fitness and promote body weight loss, as an alternative method to traditional aerobic exercise.


Assuntos
Aptidão Cardiorrespiratória , Metabolismo Energético , Perda de Peso , Ioga , Adulto , Exercício de Arrefecimento/fisiologia , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Postura/fisiologia , Fatores Sexuais , Exercício de Aquecimento/fisiologia
10.
Lancet ; 396(10253): 759-769, 2020 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-32871100

RESUMO

BACKGROUND: Cardiac muscle hypercontractility is a key pathophysiological abnormality in hypertrophic cardiomyopathy, and a major determinant of dynamic left ventricular outflow tract (LVOT) obstruction. Available pharmacological options for hypertrophic cardiomyopathy are inadequate or poorly tolerated and are not disease-specific. We aimed to assess the efficacy and safety of mavacamten, a first-in-class cardiac myosin inhibitor, in symptomatic obstructive hypertrophic cardiomyopathy. METHODS: In this phase 3, randomised, double-blind, placebo-controlled trial (EXPLORER-HCM) in 68 clinical cardiovascular centres in 13 countries, patients with hypertrophic cardiomyopathy with an LVOT gradient of 50 mm Hg or greater and New York Heart Association (NYHA) class II-III symptoms were assigned (1:1) to receive mavacamten (starting at 5 mg) or placebo for 30 weeks. Visits for assessment of patient status occurred every 2-4 weeks. Serial evaluations included echocardiogram, electrocardiogram, and blood collection for laboratory tests and mavacamten plasma concentration. The primary endpoint was a 1·5 mL/kg per min or greater increase in peak oxygen consumption (pVO2) and at least one NYHA class reduction or a 3·0 mL/kg per min or greater pVO2 increase without NYHA class worsening. Secondary endpoints assessed changes in post-exercise LVOT gradient, pVO2, NYHA class, Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS), and Hypertrophic Cardiomyopathy Symptom Questionnaire Shortness-of-Breath subscore (HCMSQ-SoB). This study is registered with ClinicalTrials.gov, NCT03470545. FINDINGS: Between May 30, 2018, and July 12, 2019, 429 adults were assessed for eligibility, of whom 251 (59%) were enrolled and randomly assigned to mavacamten (n=123 [49%]) or placebo (n=128 [51%]). 45 (37%) of 123 patients on mavacamten versus 22 (17%) of 128 on placebo met the primary endpoint (difference +19·4%, 95% CI 8·7 to 30·1; p=0·0005). Patients on mavacamten had greater reductions than those on placebo in post-exercise LVOT gradient (-36 mm Hg, 95% CI -43·2 to -28·1; p<0·0001), greater increase in pVO2 (+1·4 mL/kg per min, 0·6 to 2·1; p=0·0006), and improved symptom scores (KCCQ-CSS +9·1, 5·5 to 12·7; HCMSQ-SoB -1·8, -2·4 to -1·2; p<0·0001). 34% more patients in the mavacamten group improved by at least one NYHA class (80 of 123 patients in the mavacamten group vs 40 of 128 patients in the placebo group; 95% CI 22·2 to 45·4; p<0·0001). Safety and tolerability were similar to placebo. Treatment-emergent adverse events were generally mild. One patient died by sudden death in the placebo group. INTERPRETATION: Treatment with mavacamten improved exercise capacity, LVOT obstruction, NYHA functional class, and health status in patients with obstructive hypertrophic cardiomyopathy. The results of this pivotal trial highlight the benefits of disease-specific treatment for this condition. FUNDING: MyoKardia.


Assuntos
Benzilaminas/uso terapêutico , Miosinas Cardíacas/antagonistas & inibidores , Cardiomiopatia Hipertrófica/tratamento farmacológico , Uracila/análogos & derivados , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Benzilaminas/efeitos adversos , Bloqueadores dos Canais de Cálcio/uso terapêutico , Cardiomiopatia Hipertrófica/fisiopatologia , Fármacos Cardiovasculares/uso terapêutico , Método Duplo-Cego , Tolerância ao Exercício/fisiologia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Avaliação de Resultados da Assistência ao Paciente , Uracila/efeitos adversos , Uracila/uso terapêutico
11.
PLoS One ; 15(9): e0238863, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32886730

RESUMO

A progressive, treadmill-based VO2max is the gold standard of cardiorespiratory fitness determination but is rarely used in pediatric clinics due to time requirements and cost. Simpler and shorter fitness tests such as the Squat Test or Step Test may be feasible and clinically useful alternatives. However, performance comparisons of these tests to treadmill VO2max tests are lacking. The primary aim of this cross-sectional study was to assess the correlation between Squat and Step Test scores and VO2max in a pediatric population. As secondary outcomes, we calculated correlations between Rated Perceived Exertion Scale (RPE) scores, NIH PROMIS Physical Activity scores, and BMI z-score with VO2max, and we also evaluated the ability of each fitness test to discriminate low and high-risk patients based on the FITNESSGram. Forty children aged 10-17 completed these simple cardiorespiratory fitness tests. Statistically significant correlations were observed between VO2max and the Step Test (r = -0.549) and Squat Test (r = -0.429) scores, as well as participant BMI z-score (r = -0.458). RPE and PROMIS scores were not observed to be correlated with VO2max. Area Under the Receiver Operator Curve was relatively high for BMI z-scores and the Step Test (AUC = 0.813, 0.713 respectively), and lower for the Squat Test (AUC = 0.610) in discriminating risk according to FITNESSGram Scores. In this sample, the Step Test performed best overall. These tests were safe, feasible, and may add great value in assessing cardiorespiratory fitness in a clinical setting.


Assuntos
Aptidão Cardiorrespiratória , Fenômenos Fisiológicos Cardiovasculares , Teste de Esforço/métodos , Exercício Físico , Consumo de Oxigênio , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Valor Preditivo dos Testes
12.
J Vis Exp ; (162)2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32894267

RESUMO

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated hemoglobin molecules. A probe placed on the skin emits light that is absorbed, scattered, and reflected by the underlying tissue. Detectors in the probe sense the amount of reflected light: this reflects the organ-specific ratio of oxygen supply and consumption - independent of pulsatile flow. Modern devices enable the simultaneous monitoring at different body sites. A rise or dip in the rSO2 curve visualizes changes in oxygen supply or demand before vital signs indicate them. The evolution of rSO2 values in relation to the starting point is more important for interpretation than are absolute values. A routine clinical application of NIRS is the surveillance of somatic and cerebral oxygenation during and after cardiac surgery. It is also administered in preterm infants at risk for necrotizing enterocolitis, newborns with hypoxic ischemic encephalopathy and a potential risk of impaired tissue oxygenation. In the future, NIRS could be increasingly used in multimodal neuromonitoring, or applied to monitor patients with other conditions (e.g., after resuscitation or traumatic brain injury).


Assuntos
Estado Terminal , Oximetria/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Criança , Humanos , Lactente , Recém-Nascido , Masculino , Oximetria/instrumentação , Consumo de Oxigênio/fisiologia , Oxiemoglobinas/análise
13.
J Spec Oper Med ; 20(3): 97-102, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32969011

RESUMO

Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. "In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output." The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO)2 which is one of the primary determinants of oxygen delivery (DO2). The diminishing DO2 creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO2 with a resultant increase in systemic hypoxia. If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO2 and the potential for inducing cardiac arrest in the critically shocked patient.


Assuntos
Choque Hemorrágico , Humanos , Consumo de Oxigênio , Respiração com Pressão Positiva/efeitos adversos , Indução e Intubação de Sequência Rápida , Ressuscitação , Choque Hemorrágico/etiologia , Choque Hemorrágico/terapia
14.
Aquat Toxicol ; 228: 105630, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32971354

RESUMO

Bitumen mined in the oil sands region of Northern Alberta, Canada, is diluted with natural gas condensates to form dilbit, which is transported through pipelines. Sections of these pipelines come close to freshwater ecosystems. If dilbit is spilled into or near an aquatic environment, environmental weathering processes, such as evaporation and sediment interaction, influence the fate and toxicity of dilbit to aquatic organisms. To date, most studies of the effects of dilbit on the health of aquatic organisms have not considered weathering processes. Thus, the goal of this study was to assess the toxicity of weathered sediment-bound dilbit (WSD) to an aquatic organism. Adult freshwater amphipods (Hyalella azteca) were exposed directly to WSD or the water-soluble fraction (WSF) of WSD. Direct exposure to WSD resulted in oil-mineral aggregates adhering to the appendages and gas exchange structures of amphipods, causing acute lethality. After a 10-min exposure to WSD, amphipods consumed half as much oxygen and their appendage movement was impaired. Exposure to the WSF, which contained a total PAH concentration of 1.08 µg/L, did not result in acute lethality, or significantly affect respiration, activity or acetylcholinesterase activity. Results of the present study indicate that physical interaction with oil-mineral aggregates after a spill of dilbit is a threat to benthic invertebrates, whereas the WSF does not cause acute adverse effects. As the transport of dilbit through pipelines increases in North America, studies must incorporate environmental weathering processes when determining the effects of dilbit on aquatic organisms.


Assuntos
Anfípodes/efeitos dos fármacos , Água Doce , Sedimentos Geológicos/química , Poluentes Químicos da Água/toxicidade , Alberta , Animais , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Consumo de Oxigênio/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Solubilidade , Água/química
15.
Mar Environ Res ; 161: 105120, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32866683

RESUMO

Acanthina monodon commonly deposits its egg capsules in the intertidal zone. Capsule aerial exposure during low-tide can impact oxygen consumption rates (OCR) of embryos and intracapsular oxygen availability, and expose embryos to desiccation. OCR increased as embryonic development progressed, and was greater when capsules were submerged in seawater than when exposed to air. Oxygen available within the capsule was always less than that available in the immediate external environment, whether capsules were immersed or exposed. The highest internal oxygen concentrations were recorded during periods of air exposure for embryos in more advanced development stages. When exposed to air, capsules lost water the fastest when they contained early embryos, and suffered the highest mortalities following exposure. Collectively, these data suggest that, although encapsulation helps the embryos to develop across wildly fluctuating environmental conditions, the amount of stress the embryos experience will vary depending on their exact positioning within the intertidal zone.


Assuntos
Gastrópodes , Animais , Dessecação , Desenvolvimento Embrionário , Consumo de Oxigênio , Água do Mar
16.
PLoS One ; 15(9): e0239463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960920

RESUMO

This study aimed to investigate the effects of different playing strategies on external and internal loads in female tennis players during match play. Also, the underlying effects on the technical-tactical actions and activity profiles were examined. Twelve well-trained female players (age: 25±5 years; maximum oxygen uptake: 40.9±4.3 ml/kg/min) played points against an opponent of similar ability outdoors on red-clay courts. The players played points over five playing conditions. Before each condition, the players were instructed to apply either a passive, an active, or their own playing strategy (free play) to succeed. The five conditions were played in a randomized order, whereas the condition with the own strategy was always played first and served as control. During play, the external and internal loads were investigated by 10 Hz global positioning system, 100 Hz inertial measurement unit, short-range telemetry, capillary blood, and visual analog scale procedures. A 25 Hz video camera was used to examine the technical-tactical actions and activity profiles. Compared to the control condition, the passive, active, and mixed playing strategy conditions induce up to large effects on the external loads (running distances with high acceleration and deceleration), up to moderate effects on the internal loads (energy expenditures spent with high metabolic power, lactate concentration, and rating of effort), and up to very large effects on the technical-tactical actions (number of ground strokes and errors) and activity profiles (strokes per rally, rally duration, work to rest ratio, and effective playing time). Our study shows that passive, active, and mixed playing strategies have an impact on the external and internal loads, technical-tactical actions, and activity profiles of female tennis players during match play. This finding should be considered for practical purposes like match analyses and training procedures in the tennis environment.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Tênis/fisiologia , Aceleração , Adulto , Feminino , Sistemas de Informação Geográfica , Humanos , Ácido Láctico/metabolismo , Oxigênio/metabolismo , Consumo de Oxigênio/fisiologia , Adulto Jovem
17.
Artigo em Inglês | MEDLINE | ID: mdl-32867179

RESUMO

We compared the changes in maximum oxygen uptake (V·O2max) calculated per skeletal muscle mass (SMM) with conventional V·O2max measures in a 1-year training cycle. We hypothesized that the pattern of changes would differ between SMM-adjusted and absolute or weight-adjusted values, and the differences between groups of distinct training specialization and status will depend on the measure used. Twelve sprinters (24.7 ± 3.3 years), 10 endurance runners (25.3 ± 5.3 years), and 10 recreationally trained controls (29 ± 4.5 years) performed a treadmill test until exhaustion to determine V·O2max. Their SMM was estimated based on the dual X-ray absorptiometry method and a regression equation. The significance of differences was assessed using analysis of variance (p ≤ 0.05). The pattern of the longitudinal change was not different between V·O2max/SMM and standard measures. Also, the significance of differences between sprinters and endurance athletes remained similar regardless of the V·O2max measure. Sprinters and controls had similar absolute (~4.3 L·min-1) and total weight-adjusted (~52 vs. ~56 mL·min-1·kg) V·O2max, but they significantly differed in SMM-adjusted V·O2max (~110 vs. ~130 mL·min-1·kg SMM-1). In summary, SMM-adjusted V·O2max is not more useful than standard measures to track longitudinal changes in competitive athletes. However, it allows to better distinguish between groups or individuals differing in training status. The results of our study are limited to male athletes.


Assuntos
Atletas , Músculo Esquelético , Consumo de Oxigênio , Resistência Física , Adulto , Teste de Esforço , Humanos , Masculino , Músculo Esquelético/fisiologia , Oxigênio , Resistência Física/fisiologia , Adulto Jovem
18.
J Breath Res ; 14(4): 043001, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32969348

RESUMO

Cavity-enhanced absorption spectroscopies (CEAS) have gained importance in a wide range of applications in molecular spectroscopy. The development of optical sensors based on the CEAS techniques coupled with the continuous wave or pulsed laser sources operating in the mid-infrared or near-infrared spectral regime uniquely offers molecularly selective and ultra-sensitive detection of trace species in complex matrices including exhaled human breath. In this review, we discussed recent applications of CEAS for analyzing trace constituents within the exhaled breath matrix facilitating the non-invasive assessment of human health status. Next to a brief discussion on the mechanisms of formation of trace components found in the exhaled breath matrix related to particular disease states, existing challenges in CEAS and future development towards non-invasive clinical diagnostics will be discussed.


Assuntos
Testes Respiratórios/métodos , Expiração , Óptica e Fotônica/métodos , Animais , Humanos , Óxido Nítrico/análise , Consumo de Oxigênio , Espectroscopia de Luz Próxima ao Infravermelho
19.
J UOEH ; 42(3): 291-295, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879194

RESUMO

We report a case of a 77-year-old male who had been diagnosed with normal-flow high-pressure gradient severe aortic stenosis (AS) two years previously. In accordance with his wishes, it was decided not to perform surgery. He visited our hospital with anorexia and weight loss and was diagnosed with gastric cancer. Echocardiography showed a change to paradoxical low-flow low-pressure gradient severe AS (PLFLPG AS). A decrease in stroke volume is typically associated with a smaller LV size, but the reason for a smaller LV size in PLFLPG AS remains unclear. In this case, the change to PLFLPG AS was thought to be due to a decrease in whole body oxygen consumption, and this may help to understand the pathology.


Assuntos
Estenose da Valva Aórtica/fisiopatologia , Idoso , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/patologia , Baixo Débito Cardíaco , Progressão da Doença , Ecocardiografia , Ventrículos do Coração/patologia , Humanos , Masculino , Consumo de Oxigênio , Índice de Gravidade de Doença , Neoplasias Gástricas/complicações , Volume Sistólico
20.
J Cardiovasc Magn Reson ; 22(1): 64, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32892749

RESUMO

BACKGROUND: Pediatric cancer survivors are at increased risk of cardiac dysfunction and heart failure. Reduced peak oxygen consumption (peak VO2) is associated with impaired cardiac reserve (defined as the increase in cardiac function from rest to peak exercise) and heart failure risk, but it is unclear whether this relationship exists in pediatric cancer survivors. This study sought to investigate the presence of reduced peak VO2 in pediatric cancer survivors with increased risk of heart failure, and to assess its relationship with resting cardiac function and cardiac haemodynamics and systolic function during exercise. METHODS: Twenty pediatric cancer survivors (8-24 years; 10 male) treated with anthracycline chemotherapy ± radiation underwent cardiopulmonary exercise testing to quantify peak VO2, with a value < 85% of predicted defined as impaired peak VO2. Resting cardiac function was assessed using 2- and 3-dimensional echocardiography, with cardiac reserve quantified from resting and peak exercise heart rate, stroke volume index (SVI) and cardiac index (CI) using exercise cardiovascular magnetic resonance (CMR). RESULTS: Twelve of 20 survivors (60%) had reduced peak VO2 (70 ± 16% vs. 97 ± 14% of age and gender predicted). There were no differences in echocardiographic or CMR measurements of resting cardiac function between survivors with normal or impaired peak VO2. However, those with reduced peak VO2 had diminished cardiac reserve, with a lesser increase in CI and SVI during exercise (Interaction P < 0.01 for both), whilst the heart rate response was similar (P = 0.71). CONCLUSIONS: Whilst exercise intolerance is common among pediatric cancer survivors, it is poorly explained by resting measures of cardiac function. In contrast, impaired exercise capacity is associated with impaired haemodynamics and systolic functional reserve measured during exercise. Consequently, measures of cardiopulmonary fitness and cardiac reserve may aid in early identification of survivors with heightened risk of long-term heart failure.


Assuntos
Antraciclinas/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Sobreviventes de Câncer , Aptidão Cardiorrespiratória , Teste de Esforço , Tolerância ao Exercício , Cardiopatias/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Lesões por Radiação/diagnóstico por imagem , Adolescente , Fatores Etários , Cardiotoxicidade , Criança , Feminino , Nível de Saúde , Cardiopatias/induzido quimicamente , Cardiopatias/fisiopatologia , Hemodinâmica , Humanos , Masculino , Consumo de Oxigênio , Valor Preditivo dos Testes , Lesões por Radiação/etiologia , Lesões por Radiação/fisiopatologia , Radioterapia/efeitos adversos , Fatores de Risco , Adulto Jovem
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