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Low water intake is associated with long-term adverse health outcomes. Despite this, few studies had examined hydration physiology in the general population, where adequate intake, and not excessive loss, is the primary determinant of hydration. This study sought to evaluate the responsiveness of hydration biomarkers in urine and blood to acute changes in water intake. Key findings were that markers of urine concentration and urine volume change rapidly in response to a change in water intake, whereas plasma osmolality is maintained. Moreover, urine concentration varies as a function of the time of day, with nighttime and morning urine samples being more concentrated than afternoon samples. These results suggest that short, well-timed urine samples, such as those taken in the afternoon, may provide values comparable with 24-hour collections, which are more time-consuming and less convenient. [ABSTRACT FROM AUTHOR]

Lipopolysaccharides (LPS) are components of Gram-negative bacteria. The cellular response from the host to LPS is mediated through stepwise interactions involving the lipopolysaccharide-binding protein (LBP), CD14, and MD-2, which produces the rearrangement of TLR4. In addition to LBP, the lipid transfer/lipopolysaccharide-binding protein gene family includes the phospholipid transfer protein (PLTP). Here we show that the intravascular redistribution of LPS from the plasma lipoprotein-free fraction toward circulating lipoproteins is delayed in PLTP-deficient mice. In agreement with earlier in i,itro studies, which predicted the neutralization of the endotoxic properties of LPS when associated with lipoproteins, significant increases in the plasma concentration of proinflammatory cytokines were found in PLTP-defieient as compared with wild type mice. Similar inflammatory damage occurred in tissues from wild type and PLTP-deficient mice 24 h .after one single intraperitoneal injection of LPS but with a more severe accumulation of red blood cells in glomeruli of LPS-injeeted PLTP-deficient mice. Complementary ex vit,o experiments on isolated splenocytes from wild type and PLTP-deficient mice further supported the ability of cell-derived PLTP to prevent LPS-mediated inflammation and eytotoxicity when combined with lipoprotein acceptors. Finally, PLTP deficiency in mice led to a significant increase in LPS-induced mortality. It is concluded that increasing circulating levels of PLTP may constitute a new and promising strategy in preventing endotoxic shock. [ABSTRACT FROM AUTHOR]

Although cellular uptake of vitamin E was initially described as a passive process, recent studies in the liver and brain have shown that SR-BI (scavenger receptor class B type I) is involved in this phenomenon. As SR-BI is expressed at high levels in the intestine, the present study addressed the involvement of SR-BI in vitamin E trafficking across enterocytes. Apical uptake and efflux of the main dietary forms of vitamin E were examined using Caco-2 TC-7 cell monolayers as a model of human intestinal epithelium. (R,R,R)-γ-tocopherol bioavailability was compared between wild-type mice and mice overexpressing SR-BI in the intestine. The effect of vitamin E on enterocyte SR-BI mRNA levels was measured by real-time quantitative reverse transcription-PCR. Concentration-dependent curves for vitamin E uptake were similar for (R,R,R)-α-, (R,R,R)-γ-, and DL-α-tocopherol. (R,R,R)-α-tocopherol transport was dependent on incubation temperature, with a 60% reduction in absorption at 4 °C compared with 37 °C (p < 0.05). Vitamin E flux in enterocytes was directed from the apical to the basal side, with a relative 10-fold reduction in the transfer process when measured in the opposite direction (p < 0.05). Co-incubation with cholesterol, γ-tocopherol, or lutein significantly impaired α-tocopherol absorption. Anti-human SR-BI antibodies and BLT1 (a chemical inhibitor of lipid transport via SR-BI) blocked up to 80% of vitamin E uptake and up to 30% of apical vitamin E efflux (p < 0.05), and similar results were obtained for (R,R,R)-γ-tocopherol. SR-BI mRNA levels were not significantly modified after a 24-h incubation of Caco-2 cells with vitamin E. Finally, (R,R,R)-γ-tocopherol bioavailability was 2.7-fold higher in mice overexpressing SR-BI than in wild-type mice (p < 0.05). The present data show for the first time that vitamin E intestinal absorption is, at least in part, mediated by SR-BI. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the editor discusses an article on the background and legal implications of important California legislation enacted during the first half of the 2009-2010, California Legislature's responses to the troubled condition of the economy, and the posthumous application of the attorney-client privilege.

Mouse studies indicated that plasma phospholipid transfer protein (PLTP) determines the plasma distribution of vitamin E, a potent lipophilic antioxidant. Vitamin E distribution, antioxidant status, and titer of anti-oxidized LDLs (oxLDL) autoantibodies were evaluated in plasma from control subjects (n = 31) and type 2 diabetic patients (n = 31) with elevated plasma PLTP concentration. Unlike diabetic and control HDLs, which displayed similar vitamin E contents, diabetic VLDLs and diabetic LDLs contained fewer vitamin E molecules than normal counterparts. Plasma PLTP concentration in diabetic plasmas correlated negatively with vitamin E in VLDL+LDL, but positively with vitamin E in HDL, with an even stronger correlation with the VLDL+LDL-to-HDL vitamin E ratio. Circulating levels of oxLDL were significantly higher in diabetic plasmas than in control plasmas. Whereas the titer of IgG autoantibodies to modified LDL did not differ significantly between diabetic patients and control subjects, diabetic plasmas showed significantly lower levels of potentially protective IgM autoantibodies. The present observations support a pathophysiological role of PLTP in decreasing the vitamin E content of apolipoprotein B-containing lipoproteins, but not of HDL in plasma of type 2 diabetic patients, contributing to a greater potential for LDL oxidation. [ABSTRACT FROM AUTHOR]

Presents a study which found that phospholipid transfer protein (PLTP) deficiency reduced sperm motility and impairs fertility of mouse males. Role of epididymis in PLTP expression; Characteristics of spermatozoa from PLTP; In vitro fertilization rate of mouse oocytes by PLTP spermatozoa; Conclusions and significance of the study.

Aim: Urine concentration measured via osmolality ( U ) and specific gravity ( U ) reflects the adequacy of daily fluid intake, which has important relationships to health in pregnant (PREG) and lactating (LACT) women. Urine color ( U ) may be a practical, surrogate marker for whole-body hydration status. Purpose: To determine whether U was a valid measure of urine concentration in PREG and LACT, and pair-matched non-pregnant, non-lactating control women (CON). Methods: Eighteen PREG/LACT (age 31 ± 1 years, pre-pregnancy BMI 24.3 ± 5.9 kg m) and eighteen CON (age 29 ± 4 years, BMI 24.1 ± 3.7 kg m) collected 24-h and single-urine samples on specified daily voids at five time points (15 ± 2, 26 ± 1, and 37 ± 1 weeks gestation, 3 ± 1 and 9 ± 1 weeks postpartum during lactation; CON visits were separated by similar time intervals) for measurement of 24-h U , U , and U and single-sample U and U . Results: Twenty-four-hour U was significantly correlated with 24-h U ( r = 0.6085-0.8390, P < 0.0001) and 24-h U ( r = 0.6213-0.8985, P < 0.0001) in all groups. A 24-h U ≥ 4 (AUC = 0.6848-0.9513, P < 0.05) and single-sample U ≥ 4 (AUC = 0.9094-0.9216, P < 0.0001) indicated 24-h U ≥ 500 mOsm kg (representing inadequate fluid intake) in PREG, LACT, and CON. Conclusions: Urine color was a valid marker of urine concentration in all groups. Thus, PREG, LACT, and CON can utilize U to monitor their daily fluid balance. Women who present with a U ≥ 4 likely have a U ≥ 500 mOsm kg and should increase fluid consumption to improve overall hydration status. [ABSTRACT FROM AUTHOR]

Aim: Urine color (UC) is a practical tool for hydration assessment. The technique has been validated in adults, but has not been tested in children. Purpose: The purpose of the study was to test the validity of the urine color scale in young, healthy boys and girls, as a marker of urine concentration, investigate its diagnostic ability of detecting hypohydration and examine the ability of children to self-assess UC. Methods: A total of 210 children participated (age: 8-14 years, body mass: 43.4 ± 12.6 kg, height: 1.49 ± 0.13 m, body fat: 25.2 ± 7.8 %). Data collection included: two single urine samples (first morning and before lunch) and 24-h sampling. Hydration status was assessed via urine osmolality (UOsmo) and UC via the eight-point color scale. Results: Mean UC was 3 ± 1 and UOsmo 686 ± 223 mmol kg. UC displayed a positive relationship as a predictor of UOsmo ( R: 0.45, P < 0.001). Based on the receiver operating curve, UC has good overall classification ability for the three samples (area under the curve 85-92 %), with good sensitivity (92-98 %) and specificity (55-68 %) for detecting hypohydration. The overall accuracy of the self-assessment of UC in the morning or the noon samples ranged from 67 to 78 %. Further threshold analysis indicated that the optimal self-assessed UC threshold for hypohydration was ≥4. Conclusions: The classical eight-point urine color scale is a valid method to assess hydration in children of age 8-14 years, either by researchers or self-assessment. [ABSTRACT FROM AUTHOR]

Purpose: Human daily total water intake (TWI) has a large inter-individual range. Recently, water supplementation has been suggested as a potential preventative and therapeutic modality. Thus, we aimed to measure hydration biomarkers in women with high (HIGH) versus low (LOW) daily TWI to determine baseline differences, and the efficacy of these markers during a systematic alteration in TWI. Methods: This cohort study identified 14 HIGH [3.34 (0.56) L day] and 14 LOW [1.62 (0.48) L day] from 120 women. Next, fluid intake was decreased in HIGH [2.00 (0.21) L day] while LOW increased [3.50 (0.13) L day] across 4 days. Body mass, fluid intake, serum osmolality ( S), total plasma protein (TPP), 24 h urine osmolality, and 24 h urine volume, were measured on each day of modified TWI. Estimated plasma volume ( E) was calculated using measured body mass and hematocrit values. Results: At baseline, urinary markers and TPP differentiated HIGH from LOW [7.0 (0.3) versus 7.3 (0.3) mg dL, respectively]. Upon TWI intervention, (1) body mass decreased in HIGH [−0.7 (1.1) kg, p = 0.010)] but did not increase in LOW [+0.0 (0.6) kg, p = 0.110], (2) E decreased 2.1 (2.4) %, p = 0.004, (3) urine osmolality increased in HIGH [397 (144)-605 (230) mOsm kg, p < 0.001] and decreased in LOW [726 (248)-265 (97) mOsm kg p < 0.001], and (4) no changes of serum osmolality occurred in either HIGH or LOW (all p > 0.05). Conclusions: Urinary markers and TPP are sensitive measures to habitual high and low TWI and to changes in TWI. Both groups through urinary and some hematological responses following TWI manipulation achieved regulation of hemoconcentration. [ABSTRACT FROM AUTHOR]

While associations exist between water, hydration, and disease risk, research quantifying the dose-response effect of water on health is limited. Thus, the water intake necessary to maintain optimal hydration from a physiological and health standpoint remains unclear. The aim of this analysis was to derive a 24 h urine osmolality (UOsm) threshold that would provide an index of “optimal hydration,” sufficient to compensate water losses and also be biologically significant relative to the risk of disease. Ninety-five adults (31.5 ± 4.3 years, 23.2 ± 2.7 kg·m−2) collected 24 h urine, provided morning blood samples, and completed food and fluid intake diaries over 3 consecutive weekdays. A UOsm threshold was derived using 3 approaches, taking into account European dietary reference values for water; total fluid intake, and urine volumes associated with reduced risk for lithiasis and chronic kidney disease and plasma vasopressin concentration. The aggregate of these approaches suggest that a 24 h urine osmolality ≤500 mOsm·kg−1 may be a simple indicator of optimal hydration, representing a total daily fluid intake adequate to compensate for daily losses, ensure urinary output sufficient to reduce the risk of urolithiasis and renal function decline, and avoid elevated plasma vasopressin concentrations mediating the increased antidiuretic effort. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effects of a change in water intake on mood and sensation in 22 habitual high-volume (HIGH; 2-4 L/d) and 30 low-volume (LOW; <1.2 L/d) drinkers who were asked to respectively decrease and increase their daily water intake. Method: During baseline HIGH consumed 2.5 L and LOW 1 L of water/day. During 3 controlled intervention days HIGH's water intake was restricted to 1 L/day whereas LOW's was increased to 2.5 L water/day. Several mood scales (Bond & Lader Visual Analog Scale (VAS), Profile of Mood States, Karolinska Sleepiness Scale, Thirst & Emotional VAS) were administered at different time points during the study. ANOVA including intervention, time point and intervention by time point as fixed effects on mean values (i.e.; baseline data vs. mean of 3 intervention days) for each mood scale was performed. Results: At baseline HIGH and LOW were comparable in mood state, except for thirst scores (estimate = 17.16, p<0.001) and POMS depression-dejection scores (estimate = 0.55, p<0.05) which were both higher in the HIGH vs. LOW. In HIGH the restricted water intake resulted in a significant increase in thirst (p<0.001) and a decrease in contentedness (p<0.05), calmness (p<0.01), positive emotions (p<0.05) and vigor/activity (p<0.001). In LOW, increased water consumption resulted in a significant decrease in fatigue/inertia (p<0.001), confusion/bewilderment (p = 0.05) and thirst (p<0.001) and a trend to lower sleepiness (p = 0.07) compared to baseline. Conclusion: Increasing water intake has beneficial effects in LOW, especially sleep/wake feelings, whereas decreasing water intake has detrimental effects on HIGH's mood. These deleterious effects in HIGH were observed in some sleep/wake moods as well as calmness, satisfaction and positive emotions. [ABSTRACT FROM AUTHOR]

Biomarkers of hydration change in response to acute dehydration; however, their responsiveness to changes in fluid intake volume, without exercise or heat exposure, has not been adequately described. Moreover, patterns of circadian variation in hydration biomarkers have not been established. The study aims were to (1) assess the response of hydration biomarkers to changes in daily water intake; and (2) evaluate circadian variation in urinary and salivary biomarkers. Fifty-two adults (24.8 ± 3.1 years; 22.3 ± 1.6 kg/m; 79 % female), grouped based on habitual fluid intake (low drinkers, n = 30, <1.2 L/day; high drinkers, n = 22, >2.0 L/day), completed a 5-day inpatient crossover trial. On days 1 and 2, low drinkers received 1.0 L/day of water while high drinkers received 2.5 L/day. On days 3 through 5, intake was reversed between groups. Plasma and saliva osmolality were assessed daily at predetermined times, and all urine produced over 24 h was collected in timed intervals. ANOVA with intake (1.0 vs. 2.5 L/day), day, and time revealed that (1) urine concentration (osmolality, specific gravity, color) and volume, but not plasma nor saliva osmolality, responded to changes in water intake; (2) urinary hydration biomarkers and saliva osmolality vary as a function of the time of day; and (3) urine osmolality measured in samples collected during the afternoon most closely reflects the corresponding 24 h value. Overall, urinary hydration biomarkers are responsive to changes in water intake, and stabilize within 24 h of modifying intake volume. Moreover, short afternoon urine collections may be able to replace 24 h collections for more convenience in hydration assessment. [ABSTRACT FROM AUTHOR]

Hexaacyl lipopolysaccharide (LPS) aggregates in aqueous media, but its partially deacylated lipid A moiety forms monomers with weaker toxicity. Because plasma phospholipid transfer protein (PLTP) transfers hexaacyl LPS, its impact on metabolism and biological activity of triacyl lipid A in mice was addressed. Triacyl lipid A bound readily to plasma high-density lipoproteins (HDLs) when active PLTP was expressed [HDL-associated lipid A after 4.5 h: 59.1±16.0% of total in wild-type (WT) vs. 32.5±10.3% in PLTP-deficient mice, P<0.05]. In the opposite to hexaacyl LPS, plasma residence time of lipid A was extended by PLTP, and proinflammatory cytokines/were produced in higher amounts in WT than PLTP mice (remaining lipid A after 8 h: 53±12 vs. 357%, and IL6 concentration after 4.5 h: 45.5±5.9 vs. 14.6±7.8 ng/ml, respectively; P<0.05 in all cases). After 1 wk, onset of B16-induced melanoma was observed in only 30% of lipid A-treated WT mice, whereas >80% of the untreated WT, untreated PLTP-deficient, or lipid A-treated PLTP-deficient animals bore tumors (P<0.05 in all cases). It is concluded that PLTP is essential in mediating the association of triacyl lipid A with lipoproteins, leading to extension of its residence time and to magnification of its proinflammatory and anticancer properties. [ABSTRACT FROM AUTHOR]