Gliadin, a protein present in wheat, rye and barley, undergoes incomplete enzymatic degradation during digestion, producing an immunogenic 33-mer peptide, LQLQPF(PQPQLPY)3 PQPQPF. The special features of 33-mer that provoke a break in its tolerance leading to gliadin sensitivity and celiac disease remains elusive. Herein it is reported that 33-mer gliadin peptide was not only able to fold into PPII secondary structure, but also depending on concentration conformational transition and self-assembly proceeded under aqueous condition, pH 7.0. A 33-mer dimer is presented as one initial possible step in the self-assembly process obtained by partial electrostatics charge distribution calculation and molecular dynamics. In addition, electron microscopy experiments revealed supramolecular organization of 33-mer into colloidal nanospheres. In the presence of 1 mM sodium citrate, 1mM sodium borate, 1 mM sodium phosphate buffer, 15 mM NaCl the nanospheres were stabilized, while in water a linear organization and formation of fibrils were observed. It is hypothesized that the self-assembly process could be the result of the combination of hydrophobic effect, intramolecular hydrogen bonding and electrostatic complementarity due to 33-mer high content of proline and glutamine amino acids and its calculated non-ionic amphiphilic character. Although, performed in vitro, our experiments have revealed new features of the 33-mer gliadin peptide that could represent an important and unprecedented event in the early stage of 33-mer interaction with the gut mucosa prior to onset of inflammation. Moreover, these findings may open new perspectives for the understanding and treatment of gliadin intolerance disorders.

The mechanisms by which aldosterone increases Na(+), K(+) ATPase and sodium channel activity in cortical collecting duct and distal nephron have been extensively studied. Recent investigations demonstrate that aldosterone increases Na-H exchanger-3 (NHE-3) activity, bicarbonate transport, and H(+) ATPase in proximal tubules. However, the role of aldosterone in regulation of Na(+), K(+) ATPase in proximal tubules is unknown. We hypothesize that aldosterone increases Na(+), K(+) ATPase activity in proximal tubules through activation of the mineralocorticoid receptor (MR). Immunohistochemistry of kidney sections from human, rat, and mouse kidneys revealed that the MR is expressed in the cytosol of tubules staining positively for lotus tetragonolobus agglutinin and type IIa sodium-phosphate cotransporter (NpT2a), confirming proximal tubule localization. Adrenalectomy in Sprague Dawley rats decreased expression of MR, ENaC α, Na(+), K(+) ATPase α1, and NHE-1 in all tubules, while supplementation with aldosterone restored expression of above proteins. In human kidney proximal tubule (HKC11) cells, treatment with aldosterone resulted in translocation of MR to the nucleus and phosphorylation of SGK-1. Treatment with aldosterone also increased Na(+), K(+) ATPase-mediated (86)Rb uptake and expression of Na(+), K(+) ATPase α1 subunits in HKC11 cells. The effects of aldosterone on Na(+), K(+) ATPase-mediated (86)Rb uptake were prevented by spironolactone, a competitive inhibitor of aldosterone for the MR, and partially by mifepristone, a glucocorticoid receptor (GR) inhibitor. These results suggest that aldosterone regulates Na(+), K(+) ATPase in renal proximal tubule cells through an MR-dependent mechanism.

Ginsenoside Rb2 was transformed by recombinant glycosidase (Bgp2) into ginsenosides Rd and 20(S)-Rg3. The bgp2 gene consists of 2,430 bp that encode 809 amino acids, and this gene has homology to the glycosyl hydrolase family 2 protein domain. SDS-PAGE was used to determine that the molecular mass of purified Bgp2 was 87 kDa. Using 0.1 mg ml(-1) of enzyme in 20 mM sodium phosphate buffer at 40 °C and pH 7.0, 1.0 mg ml(-1) ginsenoside Rb2 was transformed into 0.47 mg ml(-1) ginsenoside 20(S)-Rg3 within 120 min, with a corresponding molar conversion yield of 65 %. Bgp2 hydrolyzed the ginsenoside Rb2 along the following pathway: Rb2 → Rd → 20(S)-Rg3. This is the first report of the biotransformation of ginsenoside Rb2 to ginsenoside 20(S)-Rg3 using the recombinant glycosidase.

Several methods for quantifying the purine content in food and drink have been described using high-performance liquid chromatography (HPLC). We have developed an improved HPLC method that is based on a method reported by Kaneko et al. and that is more sensitive yet simple, and suitable for determining the purine content of beer and beer-like alcoholic beverages. Quantitative HPLC separation was performed on a Shodex Asahi Pak GS-320HQ column with an isocratic elution of 150 mmol/L sodium phosphate buffer (H3PO4/NaH2PO4 = 20:100 (v/v)). The retention times for the four analytes, namely, adenine, guanine, hypoxanthine and xanthine, were 19.9, 25.0, 29.3 and 43.0 min, respectively. The resolution was good, and there was no excessive interference from the other compounds in the beverages at these retention times. Furthermore, the detection limit for all the analytes was improved to less than 0.0075 mg/L, and all the calibration curves showed good linearity (r(2) > 0.999) between 0.013 and 10 mg/L for adenine and guanine, and between 0.025 and 10 mg/L for hypoxanthine and xanthine. The pretreatment was simplified by removing some procedures and optimizing the perchloric acid hydrolysis and the enzymatic peak-shift assay. We reduced the sample dilution rate by almost 50%, and the time spent on pretreatment from 4 days to only 180 min. The recovery of the analytes from spiked samples was 94.8 - 103.8%. This method may be useful for evaluating quantitative and qualitative differences in the purine content of beer and beer-like alcoholic beverages.

Acute phosphate nephropathy or nephrocalcinosis is a tubulointerstitial nephropathy characterized by tubular calcium phosphate deposition - crystal nephropathy - and slowly progressive renal insufficiency during or following treatment with preparations containing sodium phosphate. We report a patient who developed nephrocalcinosis (crystal induced acute kidney injury) following the administration of a combination of oral and rectal sodium phosphate for treatment of postoperative constipation. A timely renal replacement therapy procedure may reverse the process of crystallization and the irreversible slope towards chronic dialysis.

Abstract

Background:

Adequate bowel preparation prior to colonic diagnostic procedures is essential to ensure adequate visualisation. Scope: This consensus aims to provide guidance as to the appropriate use of bowel preparation for a range of defined clinical circumstances. A consensus group from across Europe was convened and met to discuss appropriate bowel preparation. The use of polyethylene glycol (PEG), sodium picosulphate and sodium phosphate (NaP), together with other agents, prokinetics and simethicone, in colonoscopy and small bowel video capsule endoscopy were considered. A systematic review of the literature was carried out and additional unpublished data was obtained from the members of the consensus group where required. Recommendations were graded according to the level of evidence. Findings: PEG-based regimens are recommended first-line for both procedures, since their use is supported by good efficacy and safety data. Sodium picosulphate-based regimens are recommended second-line as their cleansing efficacy appears less than PEG-based regimens. NaP is not recommended for bowel cleansing due to the potential for renal damage and other adverse events. However, the use of NaP is acceptable in patients in whom PEG or sodium picosulphate is ineffective or not tolerated. NaP should not be used in patients with chronic kidney disease, pre-existing electrolyte disturbances, congestive heart failure, cirrhosis or a history of hypertension. The timing of the dose, dietary restrictions, use in special patient groups and recording of the quality of bowel preparation are also considered for patients undergoing colonoscopy. During the development of the guidelines the European Society of Gastrointestinal Endoscopy (ESGE) issued guidance on bowel preparation for colonoscopyThe ESGE guidelines and these consensus guidelines share many recommendations; differences between the guidelines are reviewed.

Conclusion:

The use of bowel preparation should be tailored to the individual patient and their specific clinical circumstances.

Constipation is a common complaint, frequently treated with cleansing enema. Enemas can be very effective but may cause serious adverse events, such as perforation or metabolic derangement. Our aim was to evaluate the outcome of the use of cleansing enema for acute constipation and to assess adverse events within 30 days of therapy.We performed a two-phase study: an initial retrospective and descriptive study in 2010, followed by a prospective study after intervention, in 2011. According to the results of the first phase we established guidelines for the treatment of constipation in the Emergency Department and then used these in the second phase.There were 269 and 286 cases of severe constipation in the first and second periods of the study, respectively. In the first study period, only Fleet® Enema was used, and in the second, this was changed to Easy Go enema (free of sodium phosphate). There was a 19.2% decrease in the total use of enema, in the second period of the study (P < 0.0001). Adverse events and especially, the perforation rate and the 30-day mortality in patients with constipation decreased significantly in the second phase: 3 (1.4%) versus 0 (P = 0.0001) and 8 (3.9%) versus 2 (0.7%) (P = 0.0001), for perforation and death in the first and second period of the study, respectively.Enema for the treatment of acute constipation is not without adverse events, especially in the elderly, and should be applied carefully. Perforation, hyperphosphatemia (after Fleet Enema), and sepsis may cause death in up to 4% of cases. Guidelines for the treatment of acute constipation and for enema administration are urgently needed.

New pharmaceutical research approaches are focusing on trying to alleviate the perturbed phosphate (Pi) homeostasis associated with the onset of chronic kidney disease; this includes activation of some of the nuclear receptors. We have recently reported the down regulation of the intestinal and renal sodium-phosphate (NaPi) cotransporters by the liver X receptor (LXR) agonists, and the consequent decrease of the serum Pi levels. In this review, we describe our current knowledge of the different proteins involved in the renal and intestinal actions of LXR.

Phosphorus is involved in various biological processes including membrane integrity, maintenance and inheritance of genetic materials, energy metabolism, intracellular signaling and skeletal mineralization. In addition, accumulating evidences have indicated that alteration in the levels of extracellular inorganic phosphate (Pi) itself triggers signaling to regulate gene expression and cellular functions in some cell types. In bone cells such as osteoblasts and chondrocytes, extracellular Pi modulates cell proliferation, differentiation, mineralization and apoptosis. In extraskeletal tissues, extracellular Pi also exerts various effects. For example, increased extracellular Pi results in the calcification associated with the upregulation of osteoblast marker genes in vascular smooth muscle cells. As to the mechanistic aspects, it is suggested that an increase in extracellular Pi triggers signal transduction via the PiT1 type III sodium/phosphate (Na(+)/Pi) cotransporter and ERK1/2 pathway. Unicellular organisms such as bacteria and yeast sense the environmental Pi with a protein complex located in the plasma membrane, which regulates the expression of multiple genes involved in Pi uptake and metabolism to adapt to its availability. In mammals that are multicellular organisms, Pi availability should be sensed both at a cellular level to regulate the function of each cell and as a whole body to maintain the Pi homeostasis of the extracellular fluid. Although the responsiveness to the increased extracellular Pi suggests the existence of Pi-sensing mechanism in mammalian cells as well, it is unknown whether the sensing of Pi availability at a cellular level and that at a whole-body level share the same pathway or not. This chapter will review the findings regarding the regulation of various cellular functions by extracellular Pi, and also discuss the current concept on the mechanism for Pi-sensing.

Both dexamethasone and betamethasone, given to women at risk of preterm birth, substantially improve short-term neonatal health, increase the chance of the baby being discharged home alive, and reduce childhood neurosensory disability, remaining safe into adulthood. However, it is unclear which corticosteroid is of greater benefit to mother and child.This study aims to determine whether giving dexamethasone to women at risk of preterm birth at less than 34 weeks' gestation increases the chance of their children surviving free of neurosensory disability at two years' corrected age, compared with betamethasone.Design randomised, multicentre, placebo controlled trial.Inclusion criteria women at risk of preterm birth at less than 34 weeks' gestation with a singleton or twin pregnancy and no contraindications to the use of antenatal corticosteroids and who give informed consent.Trial entry & randomisation at telephone randomisation eligible women will be randomly allocated to either the dexamethasone group or the betamethasone group, allocated a study number and corresponding treatment pack.Study groups women in the dexamethasone group will be administered two syringes of 12 mg dexamethasone (dexamethasone sodium phosphate) and women in the betamethasone group will be administered two syringes of 11.4 mg betamethasone (Celestone Chronodose). Both study groups consist of intramuscular treatments 24 hours apart.Primary study outcome death or any neurosensory disability measured in children at two years' corrected age.Sample size a sample size of 1449 children is required to detect either a decrease in death or any neurosensory disability from 27.0% to 20.1% with dexamethasone compared with betamethasone, or an increase from 27.0% to 34.5% (two-sided alpha 0.05, 80% power, 5% loss to follow up, design effect 1.2).This study will provide high-level evidence of direct relevance for clinical practice. If one drug clearly results in significantly fewer deaths and fewer disabled children then it should be used consistently in women at risk of preterm birth and would be of great importance to women at risk of preterm birth, their children, health services and communities.Trial registration number: ACTRN12608000631303.