Pharmacokinetic and metabolomic analyses of Mangiferin calcium salt in rat models of type 2 diabetes and non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver is one of the most common comorbidities of diabetes. It can cause disturbance of glucose and lipid metabolism in the body, gradually develop into liver fibrosis, and even cause liver cirrhosis. Mangiferin has a variety of pharmacological activities, especially for the improvement of glycolipid metabolism and liver injury. However, its poor oral absorption and low bioavailability limit its further clinical development and application. The modification of mangiferin derivatives is the current research hotspot to solve this problem. METHODS: The plasma pharmacokinetic of mangiferin calcium salt (MCS) and mangiferin were monitored by HPLC. The urine metabolomics of MCS were conducted by UPLC-Q-TOF-MS. RESULTS: The pharmacokinetic parameters of MCS have been varied, and the oral absorption effect of MCS was better than mangiferin. Also MCS had a good therapeutic effect on type 2 diabetes and NAFLD rats by regulating glucose and lipid metabolism. Sixteen potential biomarkers had been identified based on metabolomics which were related to the corresponding pathways including Pantothenate and CoA biosynthesis, fatty acid biosynthesis, citric acid cycle, arginine biosynthesis, tryptophan metabolism, etc. CONCLUSIONS: The present study validated the favorable pharmacokinetic profiles of MCS and the biochemical mechanisms of MCS in treating type 2 diabetes and NAFLD.

Urine salts elucidate Early Neolithic animal management at Asikli Höyük, Turkey.

The process of sheep and goat (caprine) domestication began by 9000 to 8000 BCE in Southwest Asia. The early Neolithic site at Asikli Höyük in central Turkey preserves early archaeological evidence of this transformation, such as culling by age and sex and use of enclosures inside the settlement. People's strategies for managing caprines evolved at this site over a period of 1000 years, but changes in the scale of the practices are difficult to measure. Dung and midden layers at Asikli Höyük are highly enriched in soluble sodium, chlorine, nitrate, and nitrate-nitrogen isotope values, a pattern we attribute largely to urination by humans and animals onto the site. Here, we present an innovative mass balance approach to interpreting these unusual geochemical patterns that allows us to quantify the increase in caprine management over a ~1000-year period, an approach that should be applicable to other arid land tells.

A Comparison of Iodine Status in Children and Pregnant Women After a Policy Change in the Iodized Salt Standard in Shanghai, China.

In Shanghai, a new iodized salt standard was implemented in 2012. To provide evidence to the government, we compared iodine status before (35 mg/kg) and after (30 mg/kg) adjustment in vulnerable populations living in Shanghai. The probability-proportional-to-size sampling technique was used to select at least 360 pregnant women for urine iodine test and at least 1200 students for thyroid measurement and the household salt test. Of these students, at least 360 performed urine iodine test. The median thyroid volume and the median household salt iodine concentration of children aged 8-10 years were 1.80 ml and 24.8 mg/kg in 2015, and 0.97 ml and 28.3 mg/kg in 2011. The median urine iodine concentration (UIC) of pregnant women was 126.52 and 139.77 µg/L in 2015 and 2011. All differences were statistically significant (P < 0.05). The median UIC of students was 171.40 and 181.63 µg/L in 2015 and 2011, the difference was not statistically significant. Multivariate linear regression analysis showed that thyroid volume in children was associated with sex, age, region, and household salt iodized concentration. The current iodized salt concentration meets the basic needs of the population's iodine requirements except for pregnant women. Periodic monitoring is necessary particularly in vulnerable groups.

Biocompatibility properties of surface-modified poly(dimethylsiloxane) for urinary applications.

An electronic sensor system for urinary bladder pressure monitoring requires an imbedding into a biocompatible, flexible, and liquid-impermeable material. Poly(dimethylsiloxane) (PDMS) was selected in the present set-up as packaging material because it fulfills the abovementioned requirements. However, the surface of PDMS is hydrophobic and causes undesired interactions with salts, proteins, and cells present in urine. To reduce possible interactions of urine salts in the urinary bladder, monomers, [2-(methacryloyloxy)ethyl]-dimethyl-3-sulfopropyl-ammonium hydroxide (sulfobetaine) and 2-acrylamido-2-methylpropyl sulfonic acid, were grafted onto the surface through oxygen plasma treatment. A reduction in salt deposition between the pure PDMS and the modified PDMS was observed both in vitro (artificial urine flow over the surface) and in vivo (implants into the urinary bladder of experimental pigs). Additionally, a 10-fold reduction in salt deposition was observed in vitro due to grafting of the monomers onto the surface. These modified PDMS materials proved also to be biocompatible in cell cultures, which was further confirmed by histological screening of the bladder tissue after implantation in an in vivo pig model.

Double knockout of carbonic anhydrase II (CAII) and Na(+)-Cl(-) cotransporter (NCC) causes salt wasting and volume depletion.

BACKGROUND AND AIMS: The thiazide-sensitive Na(+)-Cl(-) cotransporter NCC and the Cl(-)/HCO3(-)exchanger pendrin are expressed on apical membranes of distal cortical nephron segments and mediate salt absorption, with pendrin working in tandem with the epithelial Na(+) channel (ENaC) and the Na(+)-dependent chloride/bicarbonate exchanger (NDCBE), whereas NCC is working by itself. A recent study showed that NCC and pendrin compensate for loss of each other under basal conditions, therefore masking the role that each plays in salt reabsorption. Carbonic anhydrase II (CAII, CA2 or CAR2) plays an important role in acid-base transport and salt reabsorption in the proximal convoluted tubule and acid-base transport in the collecting duct. Animals with CAII deletion show remodeling of intercalated cells along with the downregulation of pendrin. NCC KO mice on the other hand show significant upregulation of pendrin and ENaC. Neither model shows any significant salt wasting under baseline conditions. We hypothesized that the up-regulation of pendrin is essential for the prevention of salt wasting in NCC KO mice. METHODS AND RESULTS: To test this hypothesis, we generated NCC/CAII double KO (dKO) mice by crossing mice with single deletion of NCC and CAII. The NCC/CAII dKO mice displayed significant downregulation of pendrin, along with polyuria and salt wasting. As a result, the dKO mice developed volume depletion, which was associated with the inability to concentrate urine. CONCLUSIONS: We conclude that the upregulation of pendrin is essential for the prevention of salt and water wasting in NCC deficient animals and its downregulation or inactivation will result in salt wasting, impaired water conservation and volume depletion in the setting of NCC inactivation or inhibition.

Analysis of renal stones by capillary isotachophoresis.

An analytical method for the determination of the composition of renal stones by capillary isotachophoresis with conductometric detection was developed. Using different leading/terminating electrolyte systems, the qualitative and quantitative analysis of organic compounds (urate, xanthate, oxalate) and inorganic ions (phosphate, Ca(2+), Mg(2+), Na(+), NH(4)(+)) species commonly present in mixed renal stones in three separate steps can be carried out with limits of detection about 10 µmol/L. The developed method was validated by the analysis of real samples and can be used for urinary calculi classification. In addition, it was verified that this method can also be employed for the determination of the above mentioned analytes in some other samples (bones, teeth) concerning apatite biominerals (fluoro-, carbonate-, chloro-apatite).

Usefulness of self-monitoring of urinary salt excretion in hypertensive patients.

We investigated the usefulness of measuring urinary salt excretion by using a self-monitoring device. Subjects were 34 hypertensive patients who underwent successful 24-h home urine collection five times and 25 volunteers. Four volunteers were diagnosed as having hypertension based on home blood pressure (BP) readings. All subjects were asked to measure daily urinary salt excretion for 30 days by using a self-monitoring device which estimates 24-h salt excretion by overnight urine. The mean urinary salt excretion during the 30 days was 8.36 +/- 1.52 g/day and the range (maximum-minimum value) was 5.47 +/- 20.05 g/day in all subjects. Mean urinary salt excretion decreased from 8.52 +/- 1.63 g/day for the first 10 days to 8.31 +/- 1.54 g/day for the last 10 days (p < 0.05). The mean urinary salt excretion determined by a self-monitoring device using overnight urine was positively associated with that determined by 24-h home urine for five times in the hypertensive subjects (r = 0.63, p < 0.01). Results indicate that a self-monitoring device seems to be useful to monitor daily salt intake and to guide salt restriction.

Dietary exposure of pregnant ewes to salt dictates how their offspring respond to salt.

We investigated changes in salt preference, food and water intake, renin activity and salt excretion in adult offspring from ewes that were fed a high-salt diet (14% NaCl, high-salt offsrping) or grazed saltbush (saltbush offspring) from day 60 of pregnancy until day 21 of lactation. High-salt offspring were compared to offspring born to ewes consuming a control diet (2% NaCl) and saltbush offspring were compared to offspring from ewes which grazed a control diet of dry pasture. All offspring were weaned at 3 months of age and grazed the same clover-based pasture until testing started at 8 months of age. The preference for a low-salt diet (0.5% NaCl) when offered with an alternative (7% NaCl) did not differ between the offspring groups. High-salt offspring and saltbush offspring had a lower food intake (14% and 27% respectively) and lower water intake (35% and 20% respectively) than their control offspring. Both high-salt offspring and saltbush offspring had lower basal renin activity than their respective controls. After consuming salt, the renin activity of the saltbush offspring continued to be lower than controls whereas the renin activity of the high-salt offspring became similar to controls. In general, the saltbush offspring excreted an oral salt load more rapidly, though this depended on the extent of the salt load. This important adaptation of offspring born to ewes that consumed saltbush during pregnancy may improve their ability to cope with high-salt diets such as saltbush when they consume it themselves. However, the high-salt offspring did not possess such beneficial adaptations.

Standardized peptidome profiling of human urine by magnetic bead separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

BACKGROUND: Peptidome profiling of human urine is a promising tool to identify novel disease-associated biomarkers; however, a wide range of preanalytical variables influence the results of peptidome analysis. Our aim was to develop a standardized protocol for reproducible urine peptidome profiling by means of magnetic bead (MB) separation followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). METHODS: MBs with defined surface functionalities (hydrophobic interaction, cation exchange, and metal ion affinity) were used for peptide fractionation of urine. Mass accuracy and imprecision were calculated for 9 characteristic mass signals (M(r), 1000-10,000). Exogenous variables (instrument performance, urine sampling/storage conditions, freezing conditions, and freeze-thaw cycles) and endogenous variables (pH, urine salt and protein concentrations, and blood and bacteria interferences) were investigated with urine samples from 10 male and 10 female volunteers. RESULTS: We detected 427 different mass signals in the urine of healthy donors. Within- and between-day imprecision in relative signal intensities ranged from 1% to 14% and from 4% to 16%, respectively. Weak cation-exchange and metal ion affinity MB preparations required adjustment of the urinary pH to 7. Storage time, storage temperature, the number of freeze-thaw cycles, and bacterial and blood contamination significantly influenced urine peptide patterns. Individual urine peptide patterns differed significantly within and between days. This imprecision was diminished by normalization to a urinary protein content of 3.5 microg. CONCLUSION: This reliable pretreatment protocol allows standardization of preanalytical modalities and facilitates reproducible peptidome profiling of human urine by means of MB separation in combination with MALDI-TOF MS.

Electrodialysis for recovering salts from a urine solution containing micropollutants.

Electrodialysis was investigated for the separation of micropollutants from nutrients in anthropogenic urine. In a continuously operated process, the nutrients were concentrated up to a factor of 3.2. The concentration factor was limited by water transport across the membrane. Water transport was caused by osmosis and electroosmosis, and a model was developed to describe these phenomena. The removal of several spiked micropollutants was investigated in continuous electrodialysis experiments. Ethinylestradiol was removed completely during the whole operating period. Diclofenac and carbamazepine were initially retained, but limited permeation (5-10%) occurred after longer operating times (90 days). Retentions of propranolol and ibuprofen were also high initially, but substantial breakthroughs occurred during extended operation. Considerable adsorption on the membranes was observed for all compounds. The permeation mechanism of several compounds appears to depend on the adsorbed amount on the membrane, which indicates that partitioning and diffusion mechanisms play an important role in the permeation transport. Partial desorption occurred in leaching experiments with polarity reversal, and almost quantitative desorption was observed after incubation of the membranes with Filter Count Gel Solution. Because environmental concentrations are much lower than the concentrations spiked here, it can be anticipated that operation without significant permeation is possible in practice during extended periods of time.

Fiberoptic infrared spectroscopy: a novel tool for the analysis of urine and urinary salts in situ and in real time.

OBJECTIVES: To use infrared fiberoptic spectroscopy for the analysis of urinary salts in real time and with no sample processing; and to assess the practical role of this method for the quantitative measurement of the composition of urine and for the diagnosis of urolithiasis in patients. METHODS: Urine samples were obtained from two groups of patients: 24 patients with stone formation after shock wave lithotripsy and 24 normal subjects of similar age. Infrared absorption measurements were performed in real time, using infrared transmitting silver halide fibers. The absorption data were compared with the infrared absorption spectra of aqueous solutions prepared in our laboratory, with known concentrations of known urinary salts. The results were used for the study of the chemical composition of these salts in the urine samples and for a quantitative analysis of the concentration of the salts. RESULTS: We determined the composition of the stones in 20 of the 24 patients on the basis of the characteristic absorption peaks for the oxalates, carbonates, urates, and phosphates observed in their urinary samples. Using the method mentioned above, we found the concentration of different salts in urine with an average error of 20%. CONCLUSIONS: Fiberoptic infrared spectroscopy could be used as a new diagnostic tool for detecting different urinary salts in urine, finding their chemical composition, and determining their concentrations, without any sample preparation.

Urine is a saturated equilibrium and not a metastable supersaturated solution: evidence from crystalluria and the general composition of calcium salt and uric acid calculi.

A computer algorithm is described which allows urine to be modelled as a saturated equilibrium solution with respect to any combination of the solids calcium oxalate, calcium hydrogen phosphate (brushite), amorphous calcium phosphate, uric acid, sodium hydrogen urate and ammonium hydrogen urate. It is demonstrated that this model of urine, unlike the widely accepted metastable supersaturated solution model, explains the long-known calcium salt crystalluria versus pH curves of both non-stone-forming and stone-forming urine. Further, the saturation model accounts for why most "infection" stones do not contain calcium oxalate and why most "urate" stones are composed solely of uric acid and not admixed with alkali metal hydrogen urate salts. The supersaturation model of urine cannot explain satisfactorily these well-known phenomena. For example, the supersaturation model predicts that virtually all "infection" stones should contain calcium oxalate along with calcium phosphate and, perhaps, struvite.

Changes in urinary chemical composition in healthy volunteers after consuming roselle (Hibiscus sabdariffa Linn.) juice.

The objective of this study was to evaluate the changes of urine in normal subjects after consuming roselle juice in different concentrations and durations which may help the treatment and prevention of renal stone disease. Thirty-six healthy men participated in the study, in which urinalysis, urine electrolytes and indices for measurements of concentration of urine were determined before, during and after roselle juice consumption. The urine after consumption of roselle juice showed a decrease of creatinine, uric acid, citrate, tartrate, calcium, sodium, potassium and phosphate but not oxalate in urinary excretion. The CPR values of the majority of each individual increased and means PI values decreased in phase 1. Contrarily, the CPR values of the majority of volunteers decreased and means PI values increased in phase 2. In conclusion a low dose of roselle juice (16 g/day) caused more significant decrease in salt output in the urine than a high dose (24 g/day). The urinary changes were similar to the observations on villagers with and without stones in northeastern Thailand.

The adenosine receptor antagonist, 8-phenyltheophylline, causes diuresis and saliuresis in the rat.

The diuretic and adenosine antagonist actions of two alkylxanthines have been compared in the conscious rat. 8-Phenyltheophylline (10 mg kg-1) antagonized adenosine-induced bradycardia in the rat for at least 3 h whereas enprofylline (10 mg kg-1) had no effect on this response. 8-Phenyltheophylline (10 mg kg-1) evoked diuresis and saliuresis in the rat whereas enprofylline (10 mg kg-1) had no effect on excretory parameters. These results indicate that the diuretic action of some alkylxanthines may be related to adenosine antagonism.

A risk of inaccuracy in biochemical analysis of urinary stone-forming salts.

We investigated the occasional inaccuracy in the biochemical measurement of urine by comparing the values from untreated samples to those obtained following our experimental pre-treatment regimen, which prevents precipitation and dissolves visible crystals. Discrepancies were observed between some of the paired samples, especially with regard to calcium and uric acid (urate) concentrations. Moreover, considerable differences were recognized in fresh as well as stored urine specimens. Our findings demonstrate the need to develop accurate methods of processing urine for biochemical analysis with multichannel autoanalyzers.

Para-aminobenzoate inhibition of precipitation of urine salts.

Lehmann's observation that potassium para-aminobenzoate has a "salt precipitating preventive effect" in urine was confirmed in rats. This effect persisted during the 3-week period of drug administration. There was associated no significant change in urine volume, osmolality, or per cent solids. Since there is a large clinical experience in the chronic use of even larger doses, it would appear quite feasible to determine the clinical usefulness of this property of para-aminobenzoate in the prevention of recurrent renal calculi.