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1.
BMC Infect Dis ; 21(1): 465, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34020617

RESUMO

BACKGROUND: Coronavirus Disease-2019 (COVID-19) has been declared a global pandemic since March 11th, 2020. Despite emerging reports and literature covering a broad spectrum of COVID-19 clinical manifestations, facets of COVID-19 have not been fully elucidated. To the authors' concern, sinus bradycardia as a manifestation of COVID-19-induced syndrome of inappropriate antidiuretic hormone (SIADH) has never been reported before. CASE PRESENTATION: In this paper, we report a case of a 59-year-old male patient with confirmed COVID-19 initially presented with presyncope. Further investigations reveal sinus bradycardia related to COVID-19-induced SIADH. This case highlights the possibility of immuno-neuroendocrino-cardiovascular crosstalk resulting in an atypical manifestation of COVID-19: near syncope due to sinus bradycardia. CONCLUSIONS: Another possible cause of sinus bradycardia in COVID-19 is electrolyte imbalance due to COVID-19-related SIADH.


Assuntos
Bradicardia/diagnóstico , COVID-19/diagnóstico , Síndrome de Secreção Inadequada de HAD/diagnóstico , SARS-CoV-2 , Bradicardia/complicações , Bradicardia/fisiopatologia , COVID-19/complicações , Diagnóstico Diferencial , Eletrocardiografia , Humanos , Síndrome de Secreção Inadequada de HAD/complicações , Masculino , Pessoa de Meia-Idade , Equilíbrio Hidroeletrolítico
2.
Nutrients ; 13(4)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33923890

RESUMO

AIM: The purpose of this study was to evaluate hydration status, fluid intake, sweat rate, and sweat sodium concentration in recreational tropical native runners. METHODS: A total of 102 males and 64 females participated in this study. Participants ran at their self-selected pace for 30-100 min. Age, environmental conditions, running profiles, sweat rates, and sweat sodium data were recorded. Differences in age, running duration, distance and pace, and physiological changes between sexes were analysed. A p-value cut-off of 0.05 depicted statistical significance. RESULTS: Males had lower relative fluid intake (6 ± 6 vs. 8 ± 7 mL·kg-1·h-1, p < 0.05) and greater relative fluid balance deficit (-13 ± 8 mL·kg-1·h-1 vs. -8 ± 7 mL·kg-1·h-1, p < 0.05) than females. Males had higher whole-body sweat rates (1.3 ± 0.5 L·h-1 vs. 0.9 ± 0.3 L·h-1, p < 0.05) than females. Mean rates of sweat sodium loss (54 ± 27 vs. 39 ± 22 mmol·h-1) were higher in males than females (p < 0.05). CONCLUSIONS: The sweat profile and composition in tropical native runners are similar to reported values in the literature. The current fluid replacement guidelines pertaining to volume and electrolyte replacement are applicable to tropical native runners.


Assuntos
Ingestão de Líquidos , Corrida/fisiologia , Sódio/análise , Suor/química , Clima Tropical , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Idoso , Desidratação , Feminino , Humanos , Eletrodos Íon-Seletivos , Masculino , Pessoa de Meia-Idade , Potássio/análise , Gravidade Específica , Urina , Adulto Jovem
3.
Proc Biol Sci ; 288(1948): 20203191, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33823670

RESUMO

Species that are distributed over wide geographical ranges are likely to encounter a greater diversity of environmental conditions than do narrowly distributed taxa, and thus we expect a correlation between size of geographical range and breadth of physiological tolerances to abiotic challenges. That correlation could arise either because higher physiological capacity enables range expansion, or because widely distributed taxa experience more intense (but spatially variable) selection on physiological tolerances. The invasion of oceanic habitats by amniotic vertebrates provides an ideal system with which to test the predicted correlation between range size and physiological tolerances, because all three lineages that have secondarily moved into marine habitats (mammals, birds, reptiles) exhibit morphological and physiological adaptations to excrete excess salt. Our analyses of data on 62 species (19 mammals, 18 birds, 24 reptiles) confirm that more-widely distributed taxa encounter habitats with a wider range of salinities, and that they have higher osmoregulatory ability as determined by sodium concentrations in fluids expelled from salt-excreting organs. This result remains highly significant even in models that incorporate additional explanatory variables such as metabolic mode, body size and dietary habits. Physiological data thus may help to predict potential range size and perhaps a species' vulnerability to anthropogenic disturbance.


Assuntos
Salinidade , Equilíbrio Hidroeletrolítico , Animais , Ecossistema , Geografia , Oceanos e Mares
4.
Nutrients ; 13(2)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671239

RESUMO

Whether dietary salt intake affects chronic kidney disease (CKD) progression remains unclear. We conducted a retrospective cohort study to analyze the effects of both daily salt intake (DSI) and volume status on renal outcomes in 197 CKD patients. DSI was estimated by 24-h urinary sodium excretion and volume status was assessed by the ratio of extracellular water (ECW) to total body water (TBW) measured by bioelectrical impedance analysis (BIA). We divided patients into two groups according to DSI (6 g/day) or median ECW/TBW (0.475) and compared renal outcomes of each group. Furthermore, we classified and analyzed four groups according to both DSI and ECW/TBW. The higher DSI group showed a 1.69-fold (95% confidence interval (CI) 1.12-2.57, p = 0.01) excess risk of outcome occurrence compared to the lower group. Among the four groups, compared with Group 1 (low DSI and low ECW/TBW), Group 3 (high DSI and low ECW/TBW) showed a 1.84-fold (95% CI 1.03-3.30, p = 0.04) excess risk of outcome occurrence; however, Group 2 (low DSI and high ECW/TBW) showed no significant difference. High salt intake appears to be associated with poor renal outcome independent of blood pressure (BP), proteinuria, and volume status.


Assuntos
Rim/patologia , Sódio/urina , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica , Estudos Retrospectivos , Cloreto de Sódio na Dieta/administração & dosagem , Equilíbrio Hidroeletrolítico
5.
Am J Physiol Renal Physiol ; 320(5): F748-F760, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33749322

RESUMO

The association between diabetes insipidus (DI) and chronic dietary K+ deprivation is well known, but it remains uncertain how the disorder develops and whether it is influenced by the sexual dimorphism in K+ handling. Here, we determined the plasma K+ (PK) threshold for DI in male and female mice and ascertained if DI is initiated by polydipsia or by a central or nephrogenic defect. C57BL6J mice were randomized to a control diet or to graded reductions in dietary K+ for 8 days, and kidney function and transporters involved in water balance were characterized. We found that male and female mice develop polyuria and secondary polydipsia. Altered water balance coincided with a decrease in aquaporin-2 (AQP2) phosphorylation and apical localization despite increased levels of the vasopressin surrogate marker copeptin. No change in the protein abundance of urea transporter-A1 was observed. The Na+-K+-2Cl- cotransporter decreased only in males. Desmopressin treatment failed to reverse water diuresis in K+-restricted mice. These findings indicate that even a small fall in PK is associated with nephrogenic DI (NDI), coincident with the development of altered AQP2 regulation, implicating low PK as a causal trigger of NDI. We found that PK decreased more in females, and, consequently, females were more prone to develop NDI. Together, these data indicate that AQP2 regulation is disrupted by a small decrease in PK and that the response is influenced by sexual dimorphism in K+ handling. These findings provide new insights into the mechanisms linking water and K+ balances and support defining the disorder as "potassium-dependent NDI."NEW & NOTEWORTHY This study shows that aquaporin-2 regulation is disrupted by a small fall in plasma potassium levels and the response is influenced by sexual dimorphism in renal potassium handling. The findings provided new insights into the mechanisms by which water balance is altered in dietary potassium deficiency and support defining the disorder as "potassium-dependent nephrogenic diabetes insipidus."


Assuntos
Antidiuréticos/farmacologia , Desamino Arginina Vasopressina/farmacologia , Diabetes Insípido Nefrogênico/tratamento farmacológico , Resistência a Medicamentos , Rim/efeitos dos fármacos , Deficiência de Potássio/complicações , Potássio na Dieta/metabolismo , Animais , Aquaporina 2/metabolismo , Diabetes Insípido Nefrogênico/etiologia , Diabetes Insípido Nefrogênico/metabolismo , Diabetes Insípido Nefrogênico/fisiopatologia , Modelos Animais de Doenças , Feminino , Rim/metabolismo , Rim/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Fosforilação , Deficiência de Potássio/metabolismo , Deficiência de Potássio/fisiopatologia , Potássio na Dieta/sangue , Fatores de Risco , Caracteres Sexuais , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
6.
BMC Nephrol ; 22(1): 92, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33722189

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a common manifestation among patients critically ill with SARS-CoV-2 infection (Coronavirus 2019) and is associated with significant morbidity and mortality. The pathophysiology of renal failure in this context is not fully understood, but likely to be multifactorial. The intensive care unit outcomes of patients following COVID-19 acute critical illness with associated AKI have not been fully explored. We conducted a cohort study to investigate the risk factors for acute kidney injury in patients admitted to and intensive care unit with COVID-19, its incidence and associated outcomes. METHODS: We reviewed the medical records of all patients admitted to our adult intensive care unit suffering from SARS-CoV-2 infection from 14th March 2020 until 12th May 2020. Acute kidney injury was defined using the Kidney Disease Improving Global Outcome (KDIGO) criteria. The outcome analysis was assessed up to date as 3rd of September 2020. RESULTS: A total of 81 patients admitted during this period. All patients had acute hypoxic respiratory failure and needed either noninvasive or invasive mechanical ventilatory support. Thirty-six patients (44%) had evidence of AKI (Stage I-33%, Stage II-22%, Renal Replacement Therapy (RRT)-44%). All patients with AKI stage III had RRT. Age, diabetes mellitus, immunosuppression, lymphopenia, high D-Dimer levels, increased APACHE II and SOFA scores, invasive mechanical ventilation and use of inotropic or vasopressor support were significantly associated with AKI. The peak AKI was at day 4 and mean duration of RRT was 12.5 days. The mortality was 25% for the AKI group compared to 6.7% in those without AKI. Among those received RRT and survived their illness, the renal function recovery is complete and back to baseline in all patients. CONCLUSION: Acute kidney injury and renal replacement therapy is common in critically ill patients presenting with COVID-19. It is associated with increased severity of illness on admission to ICU, increased mortality and prolonged ICU and hospital length of stay. Recovery of renal function was complete in all survived patients.


Assuntos
Injúria Renal Aguda/etiologia , COVID-19/complicações , APACHE , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/mortalidade , Injúria Renal Aguda/terapia , COVID-19/epidemiologia , Estudos de Coortes , Estado Terminal , Feminino , Mortalidade Hospitalar , Humanos , Incidência , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Recuperação de Função Fisiológica , Terapia de Substituição Renal/estatística & dados numéricos , Respiração Artificial/efeitos adversos , Fatores de Risco , Equilíbrio Hidroeletrolítico
7.
Nutrients ; 13(2)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557019

RESUMO

Although it is recognized that dehydration and acidification of the body may reduce the exercise capacity, it remains unclear whether the qualitative and quantitative shares of certain ions in the drinks used by players during the same exertion may affect the indicators of their water-electrolyte and acid-base balance. This question was the main purpose of the publication. The research was carried out on female field hockey players (n = 14) throughout three specialized training sessions, during which the players received randomly assigned fluids of different osmolarity and minerals contents. The water-electrolyte and acid-base balance of the players was assessed on the basis of biochemical blood and urine indicators immediately before and after each training session. There were statistically significant differences in the values of all examined indicators for changes before and after exercise, while the differences between the consumed drinks with different osmolarities were found for plasma osmolality, and concentrations of sodium and potassium ions and aldosterone. Therefore, it can be assumed that the degree of mineralization of the consumed water did not have a very significant impact on the indicators of water-electrolyte and acid-base balance in blood and urine.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Atletas , Bebidas , Exercício Físico/fisiologia , Minerais/administração & dosagem , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Ingestão de Líquidos/fisiologia , Feminino , Hóquei , Humanos , Concentração Osmolar , Adulto Jovem
8.
Clinics (Sao Paulo) ; 76: e1924, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33567044

RESUMO

OBJECTIVES: Positive fluid balance is frequent in critically ill patients and has been considered a potential biomarker for acute kidney injury (AKI). This study aimed to evaluate positive fluid balance as a biomarker for the early detection of AKI in critically ill patients. METHODS: This was a prospective cohort study. The sample was composed of patients ≥18 years old who stayed ≥3 days in an intensive care unit. Fluid balance, urinary output and serum creatinine were assessed daily. AKI was diagnosed by the Kidney Disease Improving Global Outcome criteria. RESULTS: The final cohort was composed of 233 patients. AKI occurred in 92 patients (40%) after a median of 3 (2-6) days following ICU admission. When fluid balance was assessed as a continuous variable, a 100-ml increase in fluid balance was independently associated with a 4% increase in the odds of AKI (OR 1.04; 95% CI 1.01-1.08). Positive fluid balance categorized using different thresholds was always significantly associated with subsequent detection of AKI. The mixed effects model showed that increased fluid balance preceded AKI by 4 to 6 days. CONCLUSION: These results suggest that a positive fluid balance might be an early biomarker for AKI development in critically ill patients.


Assuntos
Injúria Renal Aguda , Estado Terminal , Injúria Renal Aguda/diagnóstico , Adulto , Biomarcadores , Humanos , Unidades de Terapia Intensiva , Estudos Prospectivos , Equilíbrio Hidroeletrolítico
9.
Am J Physiol Cell Physiol ; 320(5): C771-C777, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33625928

RESUMO

Aquaporin (AQP) water channels facilitate passive transport of water across cellular membranes following an osmotic gradient. AQPs are expressed in a multitude of epithelia, endothelia, and other cell types where they play important roles in physiology, especially in the regulation of body water homeostasis, skin hydration, and fat metabolism. AQP dysregulation is associated with many pathophysiological conditions, including nephrogenic diabetes insipidus, chronic kidney disease, and congestive heart failure. Moreover, AQPs have emerged as major players in a multitude of cancers where high expression correlates with metastasis and poor prognosis. Besides water transport, AQPs have been shown to be involved in cellular signaling, cell migration, cell proliferation, and regulation of junctional proteins involved in cell-cell adhesion; all cellular processes which are dysregulated in cancer. This review focuses on AQPs as regulators of junctional proteins involved in cell-cell adhesion.


Assuntos
Aquaporinas/metabolismo , Moléculas de Adesão Celular/metabolismo , Adesão Celular , Neoplasias/metabolismo , Água/metabolismo , Animais , Aquaporinas/química , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Humanos , Neoplasias/patologia , Estado de Hidratação do Organismo , Conformação Proteica , Transdução de Sinais , Relação Estrutura-Atividade , Equilíbrio Hidroeletrolítico
10.
Nurs Res ; 70(2): 142-149, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33630537

RESUMO

BACKGROUND: Neonatal sepsis causes morbidity and mortality in preterm infants. Clinicians need a predictive tool for the onset of neonatal infection to expedite treatment and prevent morbidity. Abnormal thermal gradients, a central-peripheral temperature difference (CPtd) of >2°C or <0°C, and elevated heart rate characteristic (HRC) scores are associated with infection. OBJECTIVE: This article presents the protocol for the Predictive Analysis Using Temperature and Heart Rate Study. METHODS: This observational trial will enroll 440 very preterm infants to measure abdominal temperature and foot temperature every minute and HRC scores hourly for 28 days to compare infection data. Time with abnormal thermal gradients (Model 1) and elevated HRC scores (Model 2) will be compared to the onset of infections. For data analysis, CPtd (abdominal temperature - foot temperature) will be investigated as two derived variables, high CPtd (number/percentage of minutes with CPtd of >2°C) and low CPtd (number/percentage of minutes with CPtd of <0°C). In the infant-level model, the outcome yi will be an indicator of whether the infant was diagnosed with an infection in the first 28 days of life, and the high CPtd and low CPtd variables will be the average over the entire observation period, logit(yi) = ß0 + xiß1 + ziγ. For the day-level model, the outcome yit will be an indicator of whether the ith infant was diagnosed with an infection on the tth day from t = 4 through t = 28 or the day that infection is diagnosed (25 possible repeated measures), logit(yit) = ß0 + xitß1 + zitγ. It will be determined whether a model with only high CPtd or only low CPtd is superior in predicting infection. Also, the correlation of abnormal HRC scores with high CPtd and low CPtd values will be assessed. DISCUSSION: Study results will inform the design of an interventional study using temperatures and/or heart rate as a predictive tool to alert clinicians of cardiac and autonomic instability present with infection.


Assuntos
Temperatura Corporal/fisiologia , Lactente Extremamente Prematuro/fisiologia , Doenças do Prematuro/diagnóstico , Sepse Neonatal/diagnóstico , Ensaios Clínicos como Assunto , Humanos , Recém-Nascido , Doenças do Prematuro/prevenção & controle , Unidades de Terapia Intensiva Neonatal , Monitorização Fisiológica/métodos , Sepse Neonatal/prevenção & controle , Estudos Observacionais como Assunto , Equilíbrio Hidroeletrolítico/fisiologia
11.
Am J Physiol Regul Integr Comp Physiol ; 320(5): R575-R587, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33565369

RESUMO

Approximately 14% of the general population suffer from chronic kidney disease that can lead to acute kidney injury (AKI), a condition with up to 50% mortality for which there is no effective treatment. Hypertension, diabetes, and cardiovascular disease are the main comorbidities, and more than 660,000 Americans have kidney failure. ß2-Adrenergic receptors (ß2ARs) have been extensively studied in association with lung and cardiovascular disease, but with limited scope in kidney and renal diseases. ß2ARs are expressed in multiple parts of the kidney including proximal and distal convoluted tubules, glomeruli, and podocytes. Classical and noncanonical ß2AR signaling pathways interface with other intracellular mechanisms in the kidney to regulate important cellular functions including renal blood flow, electrolyte balance and salt handling, and tubular function that in turn exert control over critical physiology and pathology such as blood pressure and inflammatory responses. Nephroprotection through activation of ß2ARs has surfaced as a promising field of investigation; however, there is limited data on the pharmacology and potential side effects of renal ß2AR modulation. Here, we provide updates on some of the major areas of preclinical kidney research involving ß2AR signaling that have advanced to describe molecular pathways and identify potential drug targets some of which are currently under clinical development for the treatment of kidney-related diseases.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Receptores Adrenérgicos beta 2/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Animais , Humanos , Rim/metabolismo , Rim/fisiopatologia , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Receptores Adrenérgicos beta 2/metabolismo , Transdução de Sinais
12.
BMC Cardiovasc Disord ; 21(1): 61, 2021 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-33517880

RESUMO

BACKGROUND: Fluid overload is related to the development and prognosis of cardiac surgery-associated acute kidney injury (CSA-AKI). The study is to investigate the influence of serum creatinine (SCr) corrected by fluid balance on the prognosis of patients with cardiac surgery. METHODS: A retrospective study was conducted in 1334 patients who underwent elective cardiac surgery from January 1 to December 31, 2015. Kidney Disease: Improving Global Outcomes (KDIGO) criteria for AKI were applied to identify CSA-AKI. SCr was measured every 24 h during ICU period and was accordingly adjusted for cumulative fluid balance. Changes in SCr, defined as ∆Crea, were determined by difference between before and after adjustment for cumulative fluid balance. All patients were then divided into three groups: underestimation group (∆Crea ≥ P75), normal group (P25 < ∆Crea < P75) and overestimation group (∆Crea ≤ P25). RESULTS: The incidence of AKI increased from 29.5% to 31.8% after adjustment for fluid balance. Patients in underestimation group showed prolonged length of ICU stay compared with normal group and overestimation group (3.2 [1.0-4.0] vs 2.1 [1.0-3.0] d, P < 0.001; 3.2  [1.0-4.0] vs 2.3 [1.0-3.0] d, P < 0.001). Length of hospital stay and mechanical ventilation dependent days in underestimation group were significantly longer than normal group (P < 0.001). Multivariate analysis showed age, baseline SCr and left ventricular ejection fraction were independently associated with underestimation of creatinine. CONCLUSIONS: Cumulative fluid balance after cardiac surgery disturbs accurate measurement of serum creatinine. Patients with underestimation of SCr were associated with poor prognosis.


Assuntos
Injúria Renal Aguda/diagnóstico , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Creatinina/sangue , Hemodiluição/efeitos adversos , Rim/fisiopatologia , Equilíbrio Hidroeletrolítico , Injúria Renal Aguda/sangue , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/fisiopatologia , Adulto , Idoso , Biomarcadores/sangue , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
13.
Z Gerontol Geriatr ; 54(3): 211-216, 2021 May.
Artigo em Alemão | MEDLINE | ID: mdl-33507359

RESUMO

The assessment of the fluid balance as well as the identification of hyperhydration and dehydration often represent a diagnostic challenge, especially in older patients. In principle, various diagnostic procedures and approaches are suitable for assessment of the various facets, by which such a disorder can be recognized. The contribution of abdominal ultrasound is described and evaluated in the context of the different diagnostic procedures. An overview of the current situation with respect to assessment of the vena cava is provided. In many respects there is no strict consensus concerning the thresholds of the individual measurements and the value of the different measurements. Currently, an orthograde diameter of the inferior vena cava > 2 cm is accepted as being a good indicator for hyperhydration. Less certain are analogously derived thresholds as indicators for dehydration.


Assuntos
Veia Cava Inferior , Equilíbrio Hidroeletrolítico , Idoso , Humanos , Ultrassonografia , Veia Cava Inferior/diagnóstico por imagem
14.
Nutrients ; 13(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513989

RESUMO

Hypohydration increases physiological strain and reduces physical and technical soccer performance, but there are limited data on how fluid balance responses change between different types of sessions in professional players. This study investigated sweat and fluid/carbohydrate intake responses in elite male professional soccer players training at low and high intensities in cool and hot environments. Fluid/sodium (Na+) losses and ad-libitum carbohydrate/fluid intake of fourteen elite male soccer players were measured on four occasions: cool (wet bulb globe temperature (WBGT): 15 ± 7 °C, 66 ± 6% relative humidity (RH)) low intensity (rating of perceived exertion (RPE) 2-4, m·min-1 40-46) (CL); cool high intensity (RPE 6-8, m·min-1 82-86) (CH); hot (29 ± 1 °C, 52 ± 7% RH) low intensity (HL); hot high intensity (HH). Exercise involved 65 ± 5 min of soccer-specific training. Before and after exercise, players were weighed in minimal clothing. During training, players had ad libitum access to carbohydrate beverages and water. Sweat [Na+] (mmol·L-1), which was measured by absorbent patches positioned on the thigh, was no different between conditions, CL: 35 ± 9, CH: 38 ± 8, HL: 34 ± 70.17, HH: 38 ± 8 (p = 0.475). Exercise intensity and environmental condition significantly influenced sweat rates (L·h-1), CL: 0.55 ± 0.20, CH: 0.98 ± 0.21, HL: 0.81 ± 0.17, HH: 1.43 ± 0.23 (p =0.001), and percentage dehydration (p < 0.001). Fluid intake was significantly associated with sweat rate (p = 0.019), with no players experiencing hypohydration > 2% of pre-exercise body mass. Carbohydrate intake varied between players (range 0-38 g·h-1), with no difference between conditions. These descriptive data gathered on elite professional players highlight the variation in the hydration status, sweat rate, sweat Na+ losses, and carbohydrate intake in response to training in cool and hot environments and at low and high exercise intensities.


Assuntos
Futebol/fisiologia , Sódio/metabolismo , Suor/metabolismo , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Carboidratos , Temperatura Baixa , Desidratação , Ingestão de Alimentos , Temperatura Alta , Humanos , Masculino , Temperatura , Adulto Jovem
15.
Am J Physiol Regul Integr Comp Physiol ; 320(4): R438-R451, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33439766

RESUMO

Postnatal growth failure is a common morbidity for preterm infants and is associated with adverse neurodevelopmental outcomes. Although sodium (Na) deficiency early in life impairs somatic growth, its impact on neurocognitive functions has not been extensively studied. We hypothesized that Na deficiency during early life is sufficient to cause growth failure and program neurobehavioral impairments in later life. C57BL/6J mice were placed on low- (0.4), normal- (1.5), or high- (3 g/kg) Na chow at weaning (PD22) and continued on the diet for 3 wk (to PD40). Body composition and fluid distribution were determined serially by time-domain NMR and bioimpedance spectroscopy, and anxiety, learning, and memory were assessed using the elevated plus maze and Morris water maze paradigms in later adulthood (PD63-PD69). During the diet intervention, body mass gains were suppressed in the low- compared with normal- and high-Na groups despite similar caloric uptake rates across groups. Fat mass was reduced in males but not in females fed low-Na diet. Fat-free mass and hydration were significantly reduced in both males and females fed the low-Na diet, although rapidly corrected after return to normal diet. Measures of anxiety-like behavior and learning in adulthood were not affected by diet in either sex, yet memory performance was modified by a complex interaction between sex and early life Na intake. These data support the concepts that Na deficiency impairs growth and that the amount of Na intake which supports optimal somatic growth during early life may be insufficient to fully support neurocognitive development.


Assuntos
Comportamento Animal , Dieta Hipossódica/efeitos adversos , Sistema Nervoso/crescimento & desenvolvimento , Estado Nutricional , Sódio na Dieta/administração & dosagem , Memória Espacial , Equilíbrio Hidroeletrolítico , Fatores Etários , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal , Teste de Labirinto em Cruz Elevado , Feminino , Masculino , Camundongos Endogâmicos C57BL , Teste do Labirinto Aquático de Morris , Ganho de Peso
16.
Wilderness Environ Med ; 32(1): 27-35, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33431304

RESUMO

INTRODUCTION: Wildfire suppression is characterized by high total energy expenditure and water turnover rates. Hydration position stands outline hourly fluid intake rates. However, dose interval remains ambiguous. We aimed to determine the effects of microdosing and bolus-dosing water and microdosing and bolus-dosing carbohydrate-electrolyte solutions on fluid balance, heat stress (physiologic strain index [PSI]), and carbohydrate oxidation during extended thermal exercise. METHODS: In a repeated-measures cross-over design, subjects completed four 120-min treadmill trials (1.3 m·s-1, 5% grade, 33°C, 30% relative humidity) wearing a US Forest Service wildland firefighter uniform and a 15-kg pack. Fluid delivery approximated losses calculated from a pre-experiment familiarization trial, providing 22 doses·h-1 or 1 dose·h-1 (46±11, 1005±245 mL·dose-1). Body weight (pre- and postexercise) and urine volume (pre-, during, and postexercise) were recorded. Heart rate, rectal temperature, skin temperature, and steady-state expired air samples were recorded throughout exercise. Statistical significance (P<0.05) was determined via repeated-measures analysis of variance. RESULTS: Total body weight loss (n=11, -0.6±0.3 kg, P>0.05) and cumulative urine output (n=11, 677±440 mL, P>0.05) were not different across trials. The micro-dosed carbohydrate-electrolyte trial sweat rate was lower than that of the bolus-dosed carbohydrate-electrolyte, bolus-dosed water, and microdosed water trials (n=11, 0.8±0.2, 0.9±0.2, 0.9±0.2, 0.9±0.2 L·h-1, respectively; P<0.05). PSI was lower at 60 than 120 min (n=12, 3.6±0.7 and 4.5±0.9, respectively; P<0.05), with no differences across trials. The carbohydrate-electrolyte trial's carbohydrate oxidation was higher than water trial's (n=12, 1.5±0.3 and 0.8±0.2 g·min-1, respectively; P<0.05), with no dosing style differences. CONCLUSIONS: Equal-volume diverse fluid delivery schedules did not affect fluid balance, PSI, or carbohydrate oxidation during extended thermal work.


Assuntos
Ingestão de Líquidos , Exercício Físico , Resposta ao Choque Térmico , Equilíbrio Hidroeletrolítico , Água , Adulto , Temperatura Corporal , Metabolismo dos Carboidratos , Estudos Cross-Over , Hidratação , Temperatura Alta , Humanos
17.
Am J Physiol Regul Integr Comp Physiol ; 320(4): R377-R383, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33470188

RESUMO

(Pro)renin receptor (PRR), a 350-amino acid receptor initially thought of as a receptor for the binding of renin and prorenin, is multifunctional. In addition to its role in the renin-angiotensin system (RAS), PRR transduces several intracellular signaling molecules and is a component of the vacuolar H+-ATPase that participates in autophagy. PRR is found in the kidney and particularly in great abundance in the cortical collecting duct. In the kidney, PRR participates in water and salt balance, acid-base balance, and autophagy and plays a role in development and progression of hypertension, diabetic retinopathy, and kidney fibrosis. This review highlights the role of PRR in the development and function of the kidney, namely, the macula densa, podocyte, proximal and distal convoluted tubule, and the principal cells of the collecting duct, and focuses on PRR function in body fluid volume homeostasis, blood pressure regulation, and acid-base balance. This review also explores new advances in the molecular mechanism involving PRR in normal renal health and pathophysiological states.


Assuntos
Equilíbrio Ácido-Base , Pressão Sanguínea , Rim/metabolismo , Receptores de Superfície Celular/metabolismo , Sistema Renina-Angiotensina , Equilíbrio Hidroeletrolítico , Animais , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/fisiopatologia , Fibrose , Humanos , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Rim/crescimento & desenvolvimento , Rim/patologia , Estado de Hidratação do Organismo , Organogênese , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Transdução de Sinais
18.
Gene ; 767: 145285, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33144271

RESUMO

The genus Takifugu is a group of approximately 20 species of puffer fishes living in a wide range of salinity environments around East Asian countries. This group presents a broad spectrum of evolutionary stages adapted to anadromy as a result of speciation that occurred a short time (2-5 million years) ago on an evolutionary timescale. This group thus can be considered as a model for studying the evolutionary mechanisms of anadromy. We firstly conducted a transfer experiment from seawater to low-salinity waters on five Takifugu species: two anadromous species T. obscurus and T. ocellatus, two euryhaline wanderer marine species T. rubripes and T. niphobles, and a strictly marine species T. snyderi, and confirmed that the capacity for acclimation to hypotonic environments was associated with their life history strategies. Next, transcriptomes of the gill and intestine of these species in hypotonic condition were compared to those under hypertonic condition for each species using RNA-Sequencing so as to determine possible candidate transporters playing an important role on freshwater adaptation. As this analysis suggested that cftr, encoding an important ion transporter for seawater acclimation in the gill, and ncc, encoding a transporter that is suggested to play important osmoregulatory roles in the intestine, are important candidates, their expression was validated by quantitative real-time PCR analysis. Expression of cftr was downregulated in the gills of the four euryhaline species under the hypotonic condition, but no change was detected in the gill of stenohaline T. snyderi, which may be one reason for the poor hypotonic acclimation capacity of T. snyderi. Expression of ncc was clearly upregulated in the intestines of the two anadromous species under the hypotonic condition, but not in other three species. Different ion transporter expression patterns between the five species indicate that the transcriptional regulation of cftr in the gill and ncc in the intestine may be important for the improvement of hypotonic acclimation capacity and evolution of anadromy in the Takifugu species.


Assuntos
Transporte de Íons/genética , Takifugu/genética , Takifugu/metabolismo , Aclimatação/genética , Adaptação Fisiológica/genética , Animais , Água Doce , Regulação da Expressão Gênica/genética , Brânquias/metabolismo , Transporte de Íons/fisiologia , Concentração Osmolar , Salinidade , Água do Mar , ATPase Trocadora de Sódio-Potássio/metabolismo , Transcriptoma/genética , Equilíbrio Hidroeletrolítico/genética
19.
Clinics ; 76: e1924, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153960

RESUMO

OBJECTIVES: Positive fluid balance is frequent in critically ill patients and has been considered a potential biomarker for acute kidney injury (AKI). This study aimed to evaluate positive fluid balance as a biomarker for the early detection of AKI in critically ill patients. METHODS: This was a prospective cohort study. The sample was composed of patients ≥18 years old who stayed ≥3 days in an intensive care unit. Fluid balance, urinary output and serum creatinine were assessed daily. AKI was diagnosed by the Kidney Disease Improving Global Outcome criteria. RESULTS: The final cohort was composed of 233 patients. AKI occurred in 92 patients (40%) after a median of 3 (2-6) days following ICU admission. When fluid balance was assessed as a continuous variable, a 100-ml increase in fluid balance was independently associated with a 4% increase in the odds of AKI (OR 1.04; 95% CI 1.01-1.08). Positive fluid balance categorized using different thresholds was always significantly associated with subsequent detection of AKI. The mixed effects model showed that increased fluid balance preceded AKI by 4 to 6 days. CONCLUSION: These results suggest that a positive fluid balance might be an early biomarker for AKI development in critically ill patients.


Assuntos
Humanos , Adulto , Estado Terminal , Injúria Renal Aguda/diagnóstico , Equilíbrio Hidroeletrolítico , Biomarcadores , Estudos Prospectivos , Unidades de Terapia Intensiva
20.
J Ethnopharmacol ; 264: 113284, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32841692

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Tetrapleura tetraptera Taub. (family Fabaceae), is generally found in the lowland forest of tropical Africa. Its leaves and fruits are traditionally used in West Africa for the management of brain disorders. AIM OF THE STUDY: This study evaluated the effect of Tetrapleura tetraptera methanol fruit extract (TT) on bilateral common carotid artery occlusion-induced cerebral ischemia/reperfusion (I/R) injury in male Wistar rats. MATERIALS AND METHODS: Rats pretreated with TT for 7 days before a 30 min bilateral common carotid artery occlusion and reperfusion for 24 h were assessed for neurobehavioural deficits. Cortical, striatal and hippocampal oxidative stress, pro-inflammatory events, electrolyte imbalance and neurochemical dysfunctions, as well as hippocampal histopathological alterations, were also evaluated. HPLC-DAD analysis was performed to identify likely compounds contributing to the bioactivity of the extract. RESULTS: TT reduced I/R-induced behavioral deficits and ameliorated I/R-induced oxidative stress by restoring reduced glutathione level, increasing catalase and superoxide dismutase activities, and also reducing both lipid peroxidation and xanthine oxidase activity in the brain. TT attenuated I/R-increased myeloperoxidase and lactate dehydrogenase activities as well as disturbances in Na+ and K+ levels. Alterations elicited by I/R in the activities of Na+/K+ ATPase, complex I, glutamine synthetase, acetylcholinesterase, and dopamine metabolism were abated by TT pretreatment. TT prevented I/R-induced histological changes in the hippocampus. HPLC-DAD analysis revealed the presence of aridanin, a marker compound for Tetrapleura tetraptera, and other phytochemicals. CONCLUSIONS: These findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Frutas , Teste de Campo Aberto/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Tetrapleura , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/psicologia , Relação Dose-Resposta a Droga , Masculino , Teste de Campo Aberto/fisiologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/fisiologia
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