Urine beyond electrolytes: diagnosis through extracellular vesicles.

BACKGROUND AND OBJECTIVE: Extracellular vesicles (EV) reflect the pathophysiological state of their cells of origin and are a reservoir of renal information accessible in urine. When biopsy is not an option, EV present themselves as sentinels of function and damage, providing a non-invasive approach. However, the analysis of EV in urine requires prior isolation, which slows down and hinders transition into clinical practice. The aim of this study is to show the applicability of the "single particle interferometric reflectance imaging sensor" (SP-IRIS) technology through the ExoView® platform for the direct analysis of urine EV and proteins involved in renal function. MATERIALS AND METHODS: The ExoView® technology enables the quantification and phenotyping of EV present in urine and the quantification of their membrane and internal proteins. We have applied this technology to the quantification of urinary EV and their proteins with renal tubular expression, amnionless (AMN) and secreted frizzled-related protein 1 (SFRP1), using only 5 µl of urine. Tubular expression was confirmed by immunohistochemistry. RESULTS: The mean size of the EV analysed was 59 ± 16 nm for those captured by tetraspanin CD63, 61 ± 16 nm for those captured by tetraspanin CD81, and 59 ± 10 for tetraspanin CD9, with CD63 being the majority EV subpopulation in urine (48.92%). The distribution of AMN and SFRP1 in the three capture tetraspanins turned out to be similar for both proteins, being expressed mainly in CD63 (48.23% for AMN and 52.1% for SFRP1). CONCLUSIONS: This work demonstrates the applicability and advantages of the ExoView® technique for the direct analysis of urine EV and their protein content in relation to the renal tubule. The use of minimum volumes, 5 µl, and the total analysis time not exceeding three hours facilitate the transition of EV into daily clinical practice as sources of diagnostic information.

Evaluation of nocturnal blood pressure changes and urinary electrolyte excretion in children with enuresis.

BACKGROUND: Monosymptomatic nocturnal enuresis (MNE) is defined as involuntary nighttime urination of children over five years of age without any congenital or acquired defect in the central nervous system. Many factors, mainly nocturnal polyuria, sleep disorders, decreased bladder capacity, and bladder dysfunctions play a role in the etiology of MNE. METHODS: Eighty-three children diagnosed with MNE were included in the study. Complete blood cell count, blood biochemistry, renin, and aldosterone levels of all children were obtained. Twenty-four-hour urine samples were collected separately daytime and nighttime and urinary electrolytes were evaluated. Also, 24-hour ambulatory blood pressure monitoring (ABPM) was performed for each patient. The results were evaluated by comparing both enuretic children vs. control group and enuretic children with polyuria vs. without polyuria. RESULTS: When we compared the enuretic children and the control group in terms of urinary electrolytes, the fractional excretion of sodium (FENa) and fractional excretion of potassium (FEK) values of the enuretic group were higher than the control. The evaluation of the 24-hour ABPM findings revealed no significant difference in terms of the mean arterial pressure (MAP) and diastolic blood pressure (DBP) during the daytime and nighttime measurements. The daytime systolic blood pressure (SBP), however, was significantly lower in the enuretic group. When enuretic children with and without polyuria and the control group were compared, the nighttime, FENa, FEK, as well as nighttime urinary excretion of calcium and protein were significantly higher in enuretic children with polyuria. No difference was detected on the MAP, SBP, or DBP values. CONCLUSIONS: In conclusion, the nighttime urinary solute excretion of enuretic children was found to be higher and this condition may especially be associated with pathogenesis of nighttime polyuria. In enuretic children, nighttime blood pressure changes were not influential in the etiopathogenesis in all patient groups and multiple mechanisms may play a role in the pathogenesis of enuresis.

Bariatric Surgery Induces a Differential Effect on Plasma Aldosterone in Comparison to Dietary Advice Alone.

Background and Objectives: The pathophysiological mechanisms linking weight loss to blood pressure (BP) reduction are not completely understood. The objective of this study was to compare the effect of weight loss after Roux-en-Y gastric bypass (RYGB) on BP, renin-angiotensin-aldosterone system (RAAS), and urinary electrolytes excretion to those of dietary advice. Methods: This was a case-control prospective study including obese patients referred for RYGB (cases) and obese receiving diet advice only (controls). Ambulatory BP, plasma renin activity (PRA), plasma aldosterone concentration (PAC), and urinary electrolytes were measured before (M0) and after intervention (M3: 3 months and M12: 12 months). Results: Twenty-five patients were included in the RYGB group and twelve patients in the control group. After 12 months, weight loss (-42 ± 11.5 vs -12.3 ± 6.3 kg in the control group, p=0.001) and decrease in PAC were more pronounced in the RYGB group (-34 ± 76 vs +14 ± 45 pg/ml in the control group, p=0.002). There was no difference in PRA between both groups (-0.08 ± 1.68 vs 0.01 ± 0.37 ng/ml/h, p=0.31). Sodium excretion was more marked in the RYGB group after 3 months only (-89 ± 14.9 vs -9.9 ± 27.9 mmol/day, p=0.009). The decrease in SBP was similar between both groups (-6.9 ± 9.9 vs -7.1 ± 11.9 mmHg in the control group, p=0.96). Conclusions: Bariatric-induced weight loss induces a progressive decrease in PAC independently of PRA and sodium excretion. Whether this decrease in PAC affects target organ damage in the long term remains to be determined. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT02218112.

The Beverage Hydration Index: Influence of Electrolytes, Carbohydrate and Protein.

The beverage hydration index (BHI) facilitates a comparison of relative hydration properties of beverages using water as the standard. The additive effects of electrolytes, carbohydrate, and protein on rehydration were assessed using BHI. Nineteen healthy young adults completed four test sessions in randomized order: deionized water (W), electrolytes only (E), carbohydrate-electrolytes (C + E), and 2 g/L dipeptide (alanyl-glutamine)-electrolytes (AG + E). One liter of beverage was consumed, after which urine and body mass were obtained every 60 min through 240 min. Compared to W, BHI was higher (p = 0.007) for C + E (1.15 ± 0.17) after 120 min and for AG + E (p = 0.021) at 240 min (1.15 ± 0.20). BHI did not differ (p > 0.05) among E, C + E, or AG + E; however, E contributed the greatest absolute net effect (>12%) on BHI relative to W. Net fluid balance was lower for W (p = 0.048) compared to C + E and AG + E after 120 min. AG + E and E elicited higher (p < 0.001) overall urine osmolality vs. W. W also elicited greater reports of stomach bloating (p = 0.02) compared to AG + E and C + E. The addition of electrolytes alone (in the range of sports drinks) did not consistently improve BHI versus water; however, the combination with carbohydrate or dipeptides increased fluid retention, although this occurred earlier for the sports drink than the dipeptide beverage. Electrolyte content appears to make the largest contribution in hydration properties of beverages for young adults when consumed at rest.

The influence of parenteral protein intake on electrolyte disturbances in premature infants.

INTRODUCTION: Aggressive parenteral nutrition with delivery of high amino acid and energy doses is used to improve growth and neurodevelopmental outcomes in very low birth weight (VLBW) preterm infants. Recent findings, however, suggest that this approach may cause electrolyte imbalances. The aim of our study was to compare the prevalence of hypercalcaemia, hypophosphataemia, and hypokalaemia in 2 groups of preterm infants that received parenteral nutrition with different amounts of amino acids and to analyse perinatal and nutritional variables associated with the development of electrolyte imbalances. METHODS: We conducted a retrospective observational study comparing 2 groups of preterm infants born before 33 weeks' gestation with birth weights of less than 1500 g managed with parenteral nutrition. One of the groups received less than 3 g/kg/day of amino acids and the other received 3 g/kg//day of amino acids or more. We analysed the prevalence of electrolyte imbalances and possible associations with aggressive parenteral nutrition, adjusting for potential confounders. RESULTS: We studied 114 infants: 60 given less than 3 g/kg/day of amino acids (low-intake group) and 54 given at least 3 g/kg/day (high-intake group). The prevalence of electrolyte imbalances was similar in both groups. The prevalence of hypercalcaemia was 1.67% in the low-intake group and 1.85% in the high-intake group (P > .99), the prevalence of severe hypophosphataemia 11.7% vs 9.3%, and the prevalence of hypokalaemia 15.0% vs 11.1% (P > .99). A calcium to phosphorus ratio greater than 1.05 had a protective effect against hypophosphataemia (P = .007). CONCLUSIONS: We did not find an association between hypercalcaemia, hypophosphataemia, and hypokalaemia and the amino acid dose delivered by PN in the high-intake group of preterm infants.

Roxadustat prevents Ang II hypertension by targeting angiotensin receptors and eNOS.

The prevalence of hypertension is increasing globally, while strategies for prevention and treatment of hypertension remain limited. FG-4592 (Roxadustat) is a potentially novel, orally active small-molecule hypoxia-inducible factor (HIF) stabilizer and is being used clinically to treat chronic kidney disease (CKD) anemia. In the present study, we evaluate the effects of FG-4592 on hypertension. In an angiotensin II (Ang II) hypertension model, FG-4592 abolished hypertensive responses; prevented vascular thickening, cardiac hypertrophy, and kidney injury; downregulated AGTR1 expression; and enhanced AGTR2, endothelial NO synthase (eNOS), and HIF1α protein levels in the aortas of mice. Additionally, the levels of thiobarbituric acid reactive substances (TBARs) in blood and urine were diminished by FG-4592 treatment. In vascular smooth muscle cells, FG-4592 treatment reduced angiotensin receptor type 1 (AGTR1) and increased AGTR2 levels, while preventing Ang II-induced oxidative stress. In vascular endothelial cells, FG-4592 upregulated total and phosphorylated eNOS. Moreover, FG-4592 treatment was hypotensive in L-NAME-induced hypertension. In summary, FG-4592 treatment remarkably ameliorated hypertension and organ injury, possibly through stabilizing HIF1α and subsequently targeting eNOS, AGTR1, AGTR2, and oxidative stress. Therefore, in addition to its role in treating CKD anemia, FG-4592 could be explored as a treatment for hypertension associated with high renin angiotensin system (RAS) activity or eNOS defects.

24-h Potassium Excretion Is Associated with Components of the Metabolic Syndrome: Results from a National Survey Based on Urine Collection in Adults.

A balanced diet and weight loss are the first lines of treatment for the prevention of metabolic syndrome (MS). Dietary strategies may include changing the composition of macronutrients, adopting a particular dietary pattern as a Mediterranean diet. However, the role of micronutrients, particularly potassium, in the propensity for or treatment of the syndrome is unclear. The study aimed to examine the relationship between the presence of the MS and its risk factors and the 24-h potassium excretion as the most valid proxy for dietary intake. The analyses were performed as part of the national survey estimating sodium and other electrolytes excretion conducted between 2014-2016 in Israel. The survey included urine collection, anthropometric and blood pressure measurements, and a comprehensive medical questionnaire that included details on the intake of medications that may affect electrolyte secretion. A model was constructed to evaluate the probability for the MS. MS score and its probability were examined in relation to potassium excretion at different levels and in stratification to sex. A total of 581 participants were included in the analysis. The mean potassium excretion was 2818 ± 1417 mg. The prevalence of the MS was 18.5% among participants with above-average potassium excretion and about 10.4% among participants with lower-than-average excretion (p = 0.007). A dose-response relationship was observed between MS score and potassium: the higher the score, the lower was the excretion of potassium. Potassium excretion, rather than sodium excretion, correlated with all components of the MS and even predicted MS independently from other variables. This is the first study based on a national survey showing that potassium consumption, as represented by daily excretion in urine, is inversely related to the presence of MS components after adjustment for several leading variables and careful exclusion of participants taking drugs which may interfere in potassium excretion.

Diurnal rhythms of urine volume and electrolyte excretion in healthy young men under differing intensities of daytime light exposure.

In humans, most renal functions, including urine volume and electrolyte excretions, have a circadian rhythm. Light is a strong circadian entrainment factor and daytime-light exposure is known to affect the circadian rhythm of rectal temperature (RT). The effects of daytime-light exposure on the diurnal rhythm of urinary excretion have yet to be clarified. The aim of this study was to clarify whether and how daytime exposure to bright-light affects urinary excretions. Twenty-one healthy men (21-27 years old) participated in a 4-day study involving daytime (08:00-18:00 h) exposure to two light conditions, Dim (< 50 lx) and Bright (~ 2500 lx), in a random order. During the experiment, RT was measured continuously. Urine samples were collected every 3 ~ 4 h. Compared to the Dim condition, under the Bright condition, the RT nadir time was 45 min earlier (p = 0.017) and sodium (Na), chloride (Cl), and uric acid (UA) excretion and urine volumes were greater (all p < 0.001), from 11:00 h to 13:00 h without a difference in total daily urine volume. The present results suggest that daytime bright light exposure can induce a phase shift advance in urine volume and urinary Na, Cl, and UA excretion rhythms.

Effects of intravenous magnesium sulfate on serum calcium-regulating hormones and plasma and urinary electrolytes in healthy horses.

Intravenous magnesium sulfate (MgSO4) is used in equine practice to treat hypomagnesemia, dysrhythmias, neurological disorders, and calcium dysregulation. MgSO4 is also used as a calming agent in equestrian events. Hypercalcemia affects calcium-regulating hormones, as well as plasma and urinary electrolytes; however, the effect of hypermagnesemia on these variables is unknown. The goal of this study was to investigate the effect of hypermagnesemia on blood parathyroid hormone (PTH), calcitonin (CT), ionized calcium (Ca2+), ionized magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl-) and their urinary fractional excretion (F) after intravenous administration of MgSO4 in healthy horses. Twelve healthy female horses of 4-18 years of age and 432-600 kg of body weight received a single intravenous dose of MgSO4 (60 mg/kg) over 5 minutes, and blood and urine samples were collected at different time points over 360 minutes. Plasma Mg2+ concentrations increased 3.7-fold over baseline values at 5 minutes and remained elevated for 120 minutes (P < 0.05), Ca2+ concentrations decreased from 30-60 minutes (P < 0.05), but Na+, K+ and Cl- concentrations did not change. Serum PTH concentrations dropped initially to rebound and remain elevated from 30 to 60 minutes, while CT concentrations increased at 5 minutes to return to baseline by 10 minutes (P < 0.05). The FMg, FCa, FNa, FK, and FCl increased, while urine osmolality decreased from 30-60 minutes compared baseline (P < 0.05). Short-term experimental hypermagnesemia alters calcium-regulating hormones (PTH, CT), reduces plasma Ca2+ concentrations, and increases the urinary excretion of Mg2+, Ca2+, K+, Na+ and Cl- in healthy horses. This information has clinical implications for the short-term effects of hypermagnesemia on calcium-regulation, electrolytes, and neuromuscular activity, in particular with increasing use of Mg salts to treat horses with various acute and chronic conditions as well as a calming agent in equestrian events.

Evaluations of the curative efficacy of G. fruticosus solvent extracts in experimentally induced nephrolithiatic Wistar male rats.

BACKGROUND: In Ethiopian folk medicine, there is a claim that medicinal plants can treat urolithiasis although there is insufficient scientific evidence. The objective of this study was to evaluate the curative efficacy of Gomphocarpus fruticosus extracts in experimentally induced nephrolithiatic rats. METHODS: Urolithiasis was induced in male Wistar rats by feeding ethylene glycol in drinking water for 28 days. The curative effects were evaluated after oral administrations of 200 mg/kg of the extracts from 15 to 28 days. Urine samples were collected 1 day before sacrificing the rats. Blood, liver and kidney samples were gathered under anaesthetic condition at day 28. Crystals in the urine were also analyzed by light microscopy. RESULTS: G. fruticosus EtOAc extract reduced significantly the level of sodium (P < 0.001), whereas it was significantly elevated the levels of magnesium and citrate (P < 0.01) compared to lithiatic control. G. fruticosus BuOH extract lowered the levels of potassium (P < 0.01), calcium and phosphate in urolithiatic rats. It was also observed that G. fruticosus EtOAc extract decreased the level of oxalate in the urine (P < 0.001), whereas it was increased the levels of magnesium (P < 0.05) and citrate (P < 0.01) in serum analysis after exposure to BuOH extract. In the kidneys, CaOx crystal deposits were reduced significantly by G. fruticosus EtOAc extract (P < 0.01). CONCLUSION: It has been noted that G. fruticosus EtOAc extract was potent in treating urolithiasis. However, further study is required to assess the efficacy of the active compounds against urolithiasis.

Sexual dimorphism in the progression of type 2 diabetic kidney disease in T2DN rats.

Diabetic kidney disease (DKD) is a common complication of diabetes, which frequently leads to end-stage renal failure and increases cardiovascular disease risk. Hyperglycemia promotes renal pathologies such as glomerulosclerosis, tubular hypertrophy, microalbuminuria, and a decline in glomerular filtration rate. Importantly, recent clinical data have demonstrated distinct sexual dimorphism in the pathogenesis of DKD in people with diabetes, which impacts both severity- and age-related risk factors. This study aimed to define sexual dimorphism and renal function in a nonobese type 2 diabetes model with the spontaneous development of advanced diabetic nephropathy (T2DN rats). T2DN rats at 12- and over 48-wk old were used to define disease progression and kidney injury development. We found impaired glucose tolerance and glomerular hyperfiltration in T2DN rats to compare with nondiabetic Wistar control. The T2DN rat displays a significant sexual dimorphism in insulin resistance, plasma cholesterol, renal and glomerular injury, urinary nephrin shedding, and albumin handling. Our results indicate that both male and female T2DN rats developed nonobese type 2 DKD phenotype, where the females had significant protection from the development of severe forms of DKD. Our findings provide further evidence for the T2DN rat strain's effectiveness for studying the multiple facets of DKD.

Association of Urine Platinum With Acute Kidney Injury in Children Treated With Cisplatin for Cancer.

Cisplatin is a chemotherapeutic agent highly excreted in urine and known to cause acute kidney injury (AKI). As AKI diagnosis by serum creatinine (SCr) is usually delayed, endeavors for finding early AKI biomarkers continue. This study aims to determine if urine platinum (UP) concentration 24 hours after cisplatin infusion is associated with AKI, and to evaluate the association between urine platinum and tubular damage biomarkers: neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Children treated with cisplatin in 12 Canadian centers (April 2013 to December 2017) were included. Urine from the morning after the first cisplatin infusion of the first or second cisplatin cycle was measured for urine platinum, NGAL, and KIM-1. SCr and serum electrolytes were used to detect AKI by either SCr elevation or urinary electrolyte wasting (potassium, magnesium, phosphate). The associations of urine platinum with AKI, NGAL, and KIM-1 were assessed. A total of 115 participants (54% boys, median age, 8.5 years; interquartile range, 4.0-13.4) were included, of which 29 (25%) and 105 (91%) developed AKI defined by SCr and electrolyte criteria, respectively. Higher urine platinum was associated with higher cisplatin dose (Spearman rho, 0.21) and with younger age (Spearman rho, -0.33). Urine platinum was not associated with postinfusion AKIor KIM-1, but was weakly associated with NGAL, particularly in participants without SCr AKI (Pearson's r, 0.22). Urine platinum may be a marker of mild tubular injury but is not likely to be a useful biomarker of clinically evident AKI.

Evaluation of the diuretic effect of crude ethanol and saponin-rich extracts of Herniaria glabra L. in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Herniaria glabra L. popularly known in Morocco as "Herras lehjer" which means "Stonebreaker" in English is a plant that has been used in traditional medicine to treat edema, water retention, urinary diseases and renal problems including kidney stones. AIM OF THE STUDY: The present study aims to investigate the diuretic activity of the crude ethanol extract (CEE) and the saponin-rich extract (SRE) of the Herniaria glabra L. METHODS: CEE and SRE were prepared using maceration. SRE was obtained after using the selective liquid-liquid extraction method with organic solvents. Control (normal saline, 10 ml/kg), reference drug (furosemide 10 mg/kg) and three different doses (10 mg/kg, 50 mg/kg, 200 mg/kg) of the CEE and SRE were administered orally to male Wistar rats. The diuretic activity of the extracts was determined by measuring urine volume, urinary electrolyte and urine pH. The urine output measured at 5 h and 24 h, electrolyte concentration and pH were measured at 24 h duration. Data were analyzed by one way ANOVA followed by Dunnett's t-test. RESULTS: The findings indicated that the CEE significantly increased diuresis at 50 mg/kg and 200 mg/kg. Moreover, the SRE showed significant diuretic effect at all doses. CEE at a dose of 200 mg/kg increases the volume of urine by 81%, while SRE at a dose of 200 mg/kg increases the volume of urine by 114%. SRE demonstrated at 200 mg/kg the highest diuretic properties comparable to the reference drug. Na+, K+ and Cl- urinary excretion was also significantly increased at 50 mg/kg and 200 mg/kg of CEE and at all doses of SRE. HPLC analysis revealed the presence of the saponin aglycones, the main ones are medicagenic acid and oleanolic acid, their content in CEE 3.1 ± 0.4%, 2.4 ± 0.3% respectively and in SRE 7.9 ± 0.2%, 5.9 ± 0.3% respectively. Triterpenoid saponins could be responsible for the diuretic activity of Herniaria glabra. CONCLUSION: This study could make it useful to develop a pharmaceutical product based on purified saponin-rich extract of Herniaria glabra L. as a diuretic agent.

Fructose-Rich Diet Is a Risk Factor for Metabolic Syndrome, Proximal Tubule Injury and Urolithiasis in Rats.

Excessive consumption of fructose (FR) leads to obesity, metabolic syndrome (MS) and insulin resistance, which are known risk factors for kidney stones. The epidemiological study has suggested the association between fructose consumption and urolithiasis, but the precise mechanism is still not well understood. Male Wistar rats were assigned for 8 weeks to three groups with different FR content in diet: RD (n = 5)-regular diet with a FR < 3%; F10 (n = 6)-regular diet with an addition of 10% Fr in drinking water; F60 (n = 5)-60% FR as a solid food. Serum concentration of FR, creatinine (Cr), insulin (Ins), triglycerides (Tg), homocysteine (HCS), uric acid (UA), calcium (Ca), phosphate (Pi), magnesium (Mg) and sodium (Na) were measured. Based on 24 h urine collection the following tests were performed: urine pH, proteinuria (PCR), excretion of N-Acetyl-(D)-Glucosaminidase (NAG), monocyte chemoattractant protein (MCP-1), uric acid (uUAEx), phosphate (uPiEx), calcium (uCaEx), magnesium (uMgEx) and sodium (uNaEx). The creatinine clearance (CrCl) was calculated. Calcium deposits in kidney sections were examined using hematoxylin and eosin (HE) and von Kossa stains. The rats on F10 and F60, as compared to the RD diet, showed a tendency for lower CrCl, higher HCS level and some features of MS as higher Ins and TG levels. Interestingly, F10 (fluid) versus F60 (solid) diet led to higher serum Ins levels. F10 and F60 versus RD demonstrated higher urinary excretion of MCP-1 and NAG which were suggestive for inflammatory injury of the proximal tubule. F10 and F60 as compared to RD showed significantly lower uUAEx, although there were no differences in clearance and fractional excretion of UA. F60 versus RD induced severe phosphaturia (>30×) and natriuria (4×) and mild calciuria. F10 versus RD induced calciuria (3×), phosphaturia (2×) and mild natriuria. Calcium phosphate stones within the tubules and interstitium were found only in rats on FR diet, respectively, in two rats from the F10 group and another two in the F60 group. The rats which developed stones were characterized by significantly higher serum insulin concentration and urinary excretion of calcium and magnesium. A fructose-rich diet may promote development of calcium stones due to proximal tubule injury and metabolic syndrome.

Urine Electrolytes in the Intensive Care Unit: From Pathophysiology to Clinical Practice.

Assessment of urine concentrations of sodium, chloride, and potassium is a widely available, rapid, and low-cost diagnostic option for the management of critically ill patients. Urine electrolytes have long been suggested in the diagnostic workup of hypovolemia, kidney injury, and acid-base and electrolyte disturbances. However, due to the wide range of normal reference values and challenges in interpretation, their use is controversial. To clarify their potential role in managing critical patients, we reviewed existing evidence on the use of urine electrolytes for diagnostic and therapeutic evaluation and assessment in critical illness. This review will describe the normal physiology of water and electrolyte excretion, summarize the use of urine electrolytes in hypovolemia, acute kidney injury, acid-base, and electrolyte disorders, and suggest some practical flowcharts for the potential use of urine electrolytes in daily critical care practice.

Sensing of electrolytes in urine using a miniaturized paper-based device.

Analyzing electrolytes in urine, such as sodium, potassium, calcium, chloride, and nitrite, has significant diagnostic value in detecting various conditions, such as kidney disorder, urinary stone disease, urinary tract infection, and cystic fibrosis. Ideally, by regularly monitoring these ions with the convenience of dipsticks and portable tools, such as cellphones, informed decision making is possible to control the consumption of these ions. Here, we report a paper-based sensor for measuring the concentration of sodium, potassium, calcium, chloride, and nitrite in urine, accurately quantified using a smartphone-enabled platform. By testing the device with both Tris buffer and artificial urine containing a wide range of electrolyte concentrations, we demonstrate that the proposed device can be used for detecting potassium, calcium, chloride, and nitrite within the whole physiological range of concentrations, and for binary quantification of sodium concentration.

Preliminary analysis of serum electrolytes and body mass index in patients with and without urolithiasis.

OBJECTIVES: To compare body mass index (BMI); serum parameters; and urine parameters between patients with and without urolithiasis. METHODS: Data from 1164 patients admitted to our Department of Urology from January 2011 to July 2013 were retrospectively reviewed; 714 patients (age, 5-87 years; male:female ratio, 1.8:1) exhibited urolithiasis, and 450 patients (age, 12-94 years; male:female ratio, 3.8:1) did not. Blood and urine were collected from patients the morning after hospital admission. Serum and urine parameters were checked by an automatic biochemistry analyzer. Statistical analysis included the Mann-Whitney U test and binary logistic regression. RESULTS: Serum sodium, potassium, chloride, calcium, phosphorus, and carbon dioxide combining power significantly differed between groups. In male patients, serum sodium, calcium, and phosphorus levels were higher in the urolithiasis group, whereas serum potassium and urine pH levels were lower. In female patients, serum sodium was higher in the urolithiasis group. BMI was higher in the urolithiasis group in all patients, male and female. Respective ß-values of serum sodium and BMI in male patients were 0.077 and 0.084; in female patients, these values were 0.119 and 0.102. CONCLUSIONS: Changes in serum sodium and BMI may be involved in the pathogenesis and treatment of urolithiasis.

Hydration Efficacy of a Milk Permeate-Based Oral Hydration Solution.

Milk permeate is an electrolyte-rich, protein- and fat-free liquid with a similar carbohydrate and mineral content to that of milk. Its hydration efficacy has not been examined. The beverage hydration index (BHI) has been used to compare various beverages to water in terms of post-ingestion fluid balance and retention. Our purpose was to compare the BHI (and related physiological responses) of a novel milk permeate solution (MPS) to that of water and a traditional carbohydrate-electrolyte solution (CES). Over three visits, 12 young subjects consumed 1 L of water, CES, or MPS. Urine samples were collected immediately post-ingestion and at 60, 120, 180, and 240 min. BHI was calculated by dividing cumulative urine output after water consumption by cumulative urine output for each test beverage at each time point. The BHI for MPS was significantly higher at all time points compared to water (all p < 0.001) and CES (all p ≤ 0.01) but did not differ between CES and water at any time point. Drinking 1 L of MPS resulted in decreased cumulative urine output across the subsequent 4 h compared to water and CES, suggesting that a beverage containing milk permeate is superior to water and a traditional CES at sustaining positive fluid balance post-ingestion.

Comparison of fractional excretion of electrolytes in patients at different stages of chronic kidney disease: A cross-sectional study.

Kidney handling of electrolytes varies in different stages of chronic kidney disease (CKD). Diabetes mellitus (DM) plays an important role in CKD. Fractional excretion (FE) is an important means in clinical practice. The relationship between FE of electrolytes in patients at different stages of CKD is worth further investigating.We designed a cross-sectional study in 1 teaching hospital, consecutive CKD patients were enrolled between February 2016 and January 2017. Including clinical demographic features, laboratory examination including spot urine electrolytes, blood biochemistries, and relevant medications were determined.A total of 762 CKD patients completed the study. Of these, 218 (28.6%) had DM. Participants were grouped according to estimated glomerular filtration rate into 7 categories: hyperfiltration (HF), CKD1, CKD2, CKD3a, CKD3b, CKD4, and CKD5. Groups HF, CKD1, 2, 3a, 3b, 4 and 5 contained 83, 143, 192, 94, 82, 82, and 86 patients, respectively. FE of electrolytes tended to increase along with the decline of renal function (CKD1-CKD5) (P < .001). The relationship was similar between the DM and non-DM groups. Diabetic patients demonstrated higher FE of magnesium compared with non-DM subjects at CKD2 and CKD5 (P < .05).CKD patients showed a progressive increase in the FE of electrolytes; FE of magnesium seemed to increase more among diabetic patients with CKD, and could be a potential predictor of CKD progression.