The aim of the present study was to observe the effect of mild hypohydration on exercise performance with subjects blinded to their hydration status. Eleven male cyclists (weight 75.8 ± 6.4 kg, ...VO2peak: 64.9 ± 5.6 mL/kg/min, body fat: 12.0 ± 5.8%, Powermax: 409 ± 40 W) performed three sets of criterium‐like cycling, consisting of 20‐minute steady‐state cycling (50% peak power output), each followed by a 5‐km time trial at 3% grade. Following a familiarization trial, subjects completed the experimental trials, in counter‐balanced fashion, on two separate occasions in dry heat (30°C, 30% rh) either hypohydrated (HYP) or euhydrated (EUH). In both trials, subjects ingested 25 mL of water every 5 minutes during the steady‐state and every 1 km of the 5‐km time trials. In the EUH trial, sweat losses were fully replaced via intravenous infusion of isotonic saline, while in the HYP trial, a sham IV was instrumented. Following the exercise protocol, the subjects’ bodyweight was changed by −0.1 ± 0.1% and −1.8 ± 0.2% for the EUH and HYP trial, respectively (P < 0.05). During the second and third time trials, subjects averaged higher power output (309 ± 5 and 306 ± 5 W) and faster cycling speed (27.5 ± 3.0 and 27.2 ± 3.1 km/h) in the EUH trial compared to the HYP trial (Power: 287 ± 4 and 276 ± 5 W, Speed: 26.2 ± 2.9 and 25.5 ± 3.3 km/h, all P < 0.05). Core temperature (Tre) was higher in the HYP trial throughout the third steady‐state and 5‐km time trial (P < 0.05). These data suggest that mild hypohydration, even when subjects were unaware of their hydration state, impaired cycle ergometry performance in the heat probably due to greater thermoregulatory strain.
PURPOSEThe aim of the present study was to examine the effect of dehydration on exercise performance independently of thirst with subjects blinded of their hydration status.
METHODSSeven male ...cyclists (weight72±9 kg, body fat14±6%, VO2peak59.4±6 mlBULLET OPERATORkg·min) exercised for 2 hours on a cycle ergometer at 55% VO2peak, in a hot-dry environment (35°C, 30% rh), with a nasogastric (NG) tube under euhydrated – non-thirst (EUH-NT) and dehydrated – non-thirst (DEH-NT) conditions. In both trials, thirst was matched by drinking 25 mL of water every 5-min (300 mLBULLET OPERATORh). In the EUH-NT trial sweat losses were fully replaced by water via the NG tube (calculated from the familiarization trial). Following the 2-h of steady state, the subjects completed a 5-km cycling time trial at 4% grade.
RESULTSBody mass loss for the EUH-NT and DEH-NT after the 2-h was -0.2±0.6 and -2.2±0.4%, while after the 5-km time trial was -0.7±0.5 and 2.9±0.4%, respectively. Thirst (35±30 vs. 42±31 mm) and stomach fullness (46±21 vs. 35±20 mm) did not differ at the end of the 2-h of steady state between EUH-NT and DEH-NT trials (P>0.05). Subjects cycled faster during the 5-km time trial in the EUH-NT trial compared to the DEH-NT trial (23.2±1.5 vs. 22.3±1.8 km·h, P<0.05), by producing higher power output (295±29 vs. 276±29 W, P<0.05). During the 5-km time trial, core temperature was higher in the DEH-NT trial (39.2±0.7 °C) compared to the EUH-NT trial (38.8±0.2°C; P>0.05).
CONCLUSIONThese data indicated that hypohydration decreased cycling performance and impaired thermoregulation independently of thirst, while the subjects were unaware of their hydration status.
Our aim was to investigate the validity of osmolality from 24-h urine collection in examining the risk for calcium-oxalate (CaOx) kidney stone formation in patients with recurrent urolithiasis. Three ...hundred and twelve subjects (males/females: 184/128) from France with a history of recurrent kidney stones from confirmed or putative CaOx origin were retrospectively included in the study (46 ± 14 years, BMI: 25.3 ± 5.0 kg·m
−2
). Tiselius’ crystallization risk index (CRI) was calculated based on urinary calcium, oxalate, citrate, magnesium, and volume from 24-h samples. The diagnostic ability of 24-h urine osmolality to classify patients as high risk for kidney stone crystallization was examined through the receivers operating characteristics analysis. High risk for CaOx crystallization was defined as CRI > 1.61 and > 1.18, for males and females, respectively. The accuracy of urine osmolality to diagnose risk of CaOx stone formation (AUC, area under the curve) for females was 84.6%, with cut-off point of 501 mmol·kg
−1
(sensitivity: 83.3%, specificity: 76.0%). Males had AUC of 85.8% with threshold of 577 mmo·kg
−1
(sensitivity: 85.5%, specificity: 77.6%). A negative association was found between 24-h urine volume and osmolality (
r
= − 0.63,
P
< 0.001). Also, a positive association was found between 24-h urine osmolality and CRI (
r
= 0.65,
P
< 0.001), as well as urea excretion with CRI (
r
= 0.37,
P
< 0.001). In conclusion, urine osmolality > 501 and > 577 mmol·kg
−1
, in female and in male, respectively, was associated with a risk for CaOx kidney stone formation in patients with a history of recurrent urolithiasis. Thus, when CaOx origin is confirmed or suspected, 24-h urine osmolality provides a simple way to define individualized target of urine dilution to prevent urine crystallization and stone formation.
A bulk heterojunction photocatalyst of interfacing CaFe(2)O(4) and MgFe(2)O(4) nanoparticles is highly active for oxidative degradation of isopropyl alcohol and hydrogen production from water under ...visible light, because the exciton easily reaches the interface and dissociates to minimize recombination.
Background and Purpose
Activation of hepatic stellate cells (HSCs) is a crucial step in the pathogenesis of hepatic fibrosis. Histone deacetylase (HDAC) is an attractive target in liver fibrosis ...because it plays a key role in gene expression and cell differentiation. We have developed a HDAC inhibitor, N‐hydroxy‐7‐(2‐naphthylthio)heptanomide (HNHA), and investigated the anti‐fibrotic activity of HNHA in vitro and in vivo.
Experimental Approach
We investigated the anti‐fibrotic effect of HNHA on mouse and human HSC activation in vitro and in the liver of bile duct‐ligated (BDL) rats in vivo using cell proliferation assays, cell cycle analysis, biochemical assay, immunohistochemistry and Western blots. Liver pathology was assessed with histochemical techniques.
Key Results
HNHA inhibited proliferation and arrested the cell cycle via p21 induction in HSCs. In addition, HNHA induced apoptosis of HSCs, which was correlated with reduced COX‐2 expression, NF‐κB activation and cell death signals. HNHA restored liver function and decreased the accumulation of extracellular matrix in the liver via suppression of HSC activation in BDL rats in vivo. HNHA administration also increased survival in BDL rats.
Conclusions and Implications
HNHA improved liver function, suppressed liver fibrosis and increased survival of BDL rats, accompanied by reduction of cell growth, activation and survival of HSCs. These findings show that HNHA may be a potent anti‐fibrosis agent against hepatic fibrosis because of its multi‐targeted inhibition of HSC activity in vivo and in vitro.
Despite recent advances in methods for culturing Mycobacterium tuberculosis (MTB), the diagnostic yield of tuberculous pleural effusion (TBPE) remains unsatisfactory. However, unlike repeated sputum ...cultures of pulmonary tuberculosis, little is known about the role of repeated pleural cultures. We examined whether repeated pleural cultures are associated with increased MTB yield from TBPE.
A multicenter, retrospective cohort study was performed from January 2012 to December 2015 in South Korea. Patients were categorized into two groups: single- or repeated-culture groups. The diagnostic yield of MTB and clinical, radiological, and pleural fluid characteristics were evaluated.
Among the 329 patients with TBPE, 77 (23.4%) had repeated cultures and 252 (76.5%) had a single culture. Pleural culture was performed twice in all 77 patients in the repeated-culture group at a 1-day interval (inter-quartile range, 1.0-2.0). In the repeated-culture group, the yield of MTB from the first culture was 31.2%, which was similar to that in the single-culture group (31.2% vs. 29.8%, P = 0.887). However, the yield of MTB from the second culture (10/77, 13.0%) was more than that from the first. These results may be attributable to the insufficient immune clearance for MTB invasion into the pleural space between the first and second cultures. Over time, the yield of the second cultures decreased from 17.4% to 6.7% and then 6.3%. Finally, the overall yield of MTB in the repeated- and single-culture groups was 44.2% and 29.8% respectively (P < 0.001).
The results showed that repeated pleural cultures increased MTB yield from TBPE in human immunodeficiency virus-negative individuals. Furthermore, repeated cultures may increase yield when carried out for two consecutive days.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Lindera obtusiloba has been used in traditional medicine for the treatment of inflammation and dermatitis. In this study, we investigated the effect of topical application of Lindera obtusiloba ...water extract (LOWE) on the house dust mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD).
We established AD model in BALB/c mice by repeated local exposure of DFE/DNCB to the ears. After a topical application of LOWE on the skin lesions, the epidermal thickness, mast cell infiltration, and serum immunoglobulin E (IgE) and histamine were measured. In addition, the gene expression of interleukin (IL)-4, IL-13, IL-31, and tumor necrosis factor (TNF)-α in the ears was assayed.
LOWE reduced AD symptoms based on ear thickness, histopathological analysis, and serum IgE levels. LOWE inhibited mast cell infiltration into the ear and elevation of serum histamine in AD model. Moreover, LOWE suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-31, and TNF-α in the ears.
Our results showed that topical application of LOWE exerts beneficial effects in AD symptoms, suggesting that LOWE might be a candidate for the treatment of AD.
Purpose
Although low water intake has been associated with adverse health outcomes, available literature indicated that the majority of children do not meet the water intake guidelines and they are ...underhydrated based on elevated hydration biomarkers. This review examined the water intake habits and hydration status in children from 32 observational studies (
n
= 36813).
Methods
PubMed, Web of Science, and CINAHL were used to identify relevant articles. Total water/fluid intake from 25 countries was compared with water intake recommendations and underhydration (urine osmolality greater than 800 mmol kg
−1
) was assessed. Risk of bias was assessed using customized categories following the review guideline for observational studies.
Results
From 32 studies, only 11 studies reported both water intake and hydration status. 12 out of 24 studies reported mean/median water/fluid intake below the guidelines, while 4 out of 13 studies that assessed hydration status indicated underhydration based on urine osmolality (greater than 800 mmol kg
−1
). Among the 19 countries that reported comparison of water/fluid intake with guidelines, 60 ± 24% of children (range 10–98%) failed to meet them.
Conclusion
These findings suggest that children are not consuming enough water to be adequately hydrated.
Deuterium oxide (D2O) appearance in blood is a marker of fluid bioavailability. However, whether biomarker robustness (e.g., relative fluid delivery speed) is consistent across analytical methods ...(e.g., cavity ring-down spectroscopy) remains unclear. Fourteen men ingested fluid (6 ml/kg body mass) containing 0.15 g/kg D2O followed by 45 min blood sampling. Plasma (D2O) was detected (n = 8) by the following: isotope-ratio mass spectrometry after vapor equilibration (IRMS-equilibrated water) or distillation (IRMS-plasma) and cavity ring-down spectroscopy. Two models calculated D2O halftime to peak (t1/2max): sigmoid curve fit versus asymmetric triangle (TRI). Background (D2O) differed (p < .001, η2 = .98) among IRMS-equilibrated water, IRMS-plasma, and cavity ring-down spectroscopy (152.2 ± 0.8, 147.2 ± 1.5, and 137.7 ± 2.2 ppm), but did not influence (p > .05) D2O appearance (Δppm), time to peak, or t1/2max. Stratifying participants based on mean t1/2max (12 min) into "slow" versus "fast" subgroups resulted in a 5.8 min difference (p < .001, η2 = .73). Significant t1/2max model (p = .01, η2 = .44) and Model × Speed Subgroup interaction (p = .005, η2 = .50) effects were observed. Bias between TRI and sigmoid curve fit increased with t1/2max speed: no difference (p = .75) for fast (9.0 min vs. 9.2 min, respectively) but greater t1/2max (p = .001) with TRI for the slow subgroup (16.1 min vs. 13.7 min). Fluid bioavailability markers are less influenced by which laboratory method is used to measure D2O as compared with the individual variability effects that influence models for calculating t1/2max. Thus, TRI model may not be appropriate for individuals with slow fluid delivery speeds.
Background: Arginine vasopressin (AVP), a key hormone in fluid balance, may be a modifiable contributor to hyperglycemia <xref ref-type="bibr" rid="ref1">1 . Low daily water drinkers often exhibit ...increased urine concentration and copeptin, a surrogate marker for AVP <xref ref-type="bibr" rid="ref2">2 , <xref ref-type="bibr" rid="ref3">3 . Objective: The primary purpose was to investigate the acute effect of adequate water intake on daily glucose concentration in low drinkers. Secondarily, the study examined if adequate water intake could improve glucoregulatory hormonal profiles in low drinkers. Methods: Seven healthy (5 males, 2 females; age 43 ± 7 years, BMI 31 ± 3) low drinkers were recruited using a water frequency questionnaire and a 24-h urine sample. Participants were recruited using social media channels and flyers in local community. Classification of a low drinker was defined by a fluid intake (water and other beverages) <1.5 L·day −1 in males or <1.0 L·day −1 in females and a 24-h·UOsm of >800 mmol·kg −1 . In a crossover counterbalanced design, participants remained in the laboratory for 11 h (07:00–18:00) and were provided either the Institute of Medicine’s recommended amount of water excluding fluid from food (males: 3 L·day −1 , females: 2 L·day −1 ; high water intake, HWI) or an amount representing the bottom quartile of water consumption observed in the National Health and Nutrition Examination Survey (males: 0.5 L·day −1 , females: 0.4 L·day −1 ; low iater intake, LWI) (Table 1) <xref ref-type="bibr" rid="ref4">4 , <xref ref-type="bibr" rid="ref5">5 . Caloric intake was standardized to body weight (100 kJ·kg −1 ) with an identical ratio of macronutrients and time of consumption between trials (Table 1). At 07:00, fasted baseline blood was drawn. Subsequent blood draws performed across the next 11 hours were analyzed for copeptin, glucose, insulin, glucagon, cortisol, and GLP-1 (Table 1). All urine voids during the 11-h protocol were pooled and analyzed for osmolality and glucose (n = 4). A two-way (water intake × time) repeated-measures ANOVA was used to determine differences in hydration and glucoregulatory measures. Dependent t tests were used to measure differences in urine samples. Statistical significance was determined a priori at an alpha of 0.05. Results: Participants were confirmed as low drinkers according to daily fluid intake, 24-h·UOsm, and copeptin (water frequency questionnaire volume: 823 ± 403 mL·day −1 , 24-h·UOsm: 961 ± 105 mmol·kg −1 , copeptin: 8.17 ± 3.05 pmol·L −1 ). During the experiments, 11-h·UOsm (HWI: 224 ± 48 mmol·kg −1 , LWI: 956 ± 120 mmol·kg −1 ), plasma osmolality, and copeptin were lower in HWI as than in LWI (p = < 0.05, Fig. 1). There was a borderline significant main effect of water intake on plasma glucose (p = 0.07, Fig. 2) and total urinary glucose output (HWI: 51.4 ± 6.9 mg, LWI: 40.1 ± 10.4 mg, p = 0.07). Cortisol was significantly higher in LWI as than in HWI (p = 0.009, Fig. 2); however, no pairwise differences were observed in post hoc analysis. Glucagon, insulin, and GLP-1 were similar between trials (p > 0.05). Conclusion: Acute increases in water intake may mildly reduce daily plasma glucose concentrations in low drinkers. This may be due to acutely increased urinary glucose output when low drinkers are given adequate amounts of water. Increased water intake also led to decreased cortisol concentration.
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