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A novel, simple, rapid, 7-minute HPLC-DAD method for the determination of 10 phenolic compounds and abscisic acid commonly found in teas, wines, fruit and honey was successfully developed and validated according to the International Council of Harmonization (ICH) guidelines. This reverse-phase (RP) HPLC-DAD method boasts rapid separation and excellent resolution while introducing green chemistry techniques. The Agilent 1200 series diode array detector SL coupled with a reverse-phase Advanced Materials Technology Halo C18 column (100 × 3.0 mm i.d., 2.7 μm) contributed to the rapid analyses. This, together with a 0.1% formic acid in water (v/v) and methanol mobile phase, a flow rate of 0.8 mL/min and the utilization of a meticulous gradient elution resulted in a validated method for the determination of 10 phenolic compounds and abscisic acid commonly found in various foodstuffs. The resulting method proved to be rapid, accurate, precise and linear with sensitive detection limits from 0.025 μg/mL to 0.500 μg/mL and percentage recoveries of 98.07%–101.94%. Phenolic compounds have been acknowledged throughout literature for their therapeutic properties, interalia, antioxidant, anti-inflammatory and antiaging due to free radical scavenging potentials. However, resulting analysis, can be frequently complicated and long and very often discounts green chemistry techniques. The developed and validated method successfully and rapidly analyses, gallic acid, caffeic acid, trans-p-coumaric acid, rutin, myricetin, abscisic acid, trans-cinnamic acid, quercetin, luteolin, kaempferol and chrysin with excellent resolution and precision.

Expression quantitative trait loci (eQTL) studies illuminate the genetics of gene expression and, in disease research, can be particularly illuminating when using the tissues directly impacted by the condition. In nephrology, there is a paucity of eQTL studies of human kidney. Here, we used whole-genome sequencing (WGS) and microdissected glomerular (GLOM) and tubulointerstitial (TI) transcriptomes from 187 individuals with nephrotic syndrome (NS) to describe the eQTL landscape in these functionally distinct kidney structures. Using MatrixEQTL, we performed cis-eQTL analysis on GLOM (n = 136) and TI (n = 166). We used the Bayesian “Deterministic Approximation of Posteriors” (DAP) to fine-map these signals, eQTLBMA to discover GLOM- or TI-specific eQTLs, and single-cell RNA-seq data of control kidney tissue to identify the cell type specificity of significant eQTLs. We integrated eQTL data with an IgA Nephropathy (IgAN) GWAS to perform a transcriptome-wide association study (TWAS). We discovered 894 GLOM eQTLs and 1,767 TI eQTLs at FDR < 0.05. 14% and 19% of GLOM and TI eQTLs, respectively, had >1 independent signal associated with its expression. 12% and 26% of eQTLs were GLOM specific and TI specific, respectively. GLOM eQTLs were most significantly enriched in podocyte transcripts and TI eQTLs in proximal tubules. The IgAN TWAS identified significant GLOM and TI genes, primarily at the HLA region. In this study, we discovered GLOM and TI eQTLs, identified those that were tissue specific, deconvoluted them into cell-specific signals, and used them to characterize known GWAS alleles. These data are available for browsing and download via our eQTL browser, “nephQTL.”

Objective In chronic kidney disease (CKD), dietary acid may promote metabolic acidosis and insulin resistance, which in turn may contribute to adverse clinical health outcomes. We examined associations between dietary acid load, serum bicarbonate, and insulin sensitivity in CKD. Design In a cross-sectional study, we collected 3-day prospective food diaries to quantify dietary acid load as net endogenous acid production (NEAP, the nonvolatile acid load produced by the diet's acid balance) and potential renal acid load (PRAL). We measured urine net acid excretion (NAE) in 24-hour urine samples. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp. Subjects Forty-two patients with CKD Stages 3 to 5 attending nephrology clinics in the Pacific Northwest and 21 control subjects (estimated glomerular filtration rate [eGFR] ≥ 60 mL/minute/1.73 m 2 ). Main Outcome Measures Serum bicarbonate and insulin sensitivity (SI clamp ). Results Mean age was 60.8 ± 13.6 years, and 54% of participants were men. Mean eGFR and serum bicarbonate concentrations were 34.4 ± 13.1 mL/minute/1.73 m 2 and 24.1 ± 2.9 mEq/L for participants with CKD and 88.6 ± 14.5 mL/minute/1.73 m 2 and 26.3 ± 1.8 mEq/L for control subjects, respectively. Mean NEAP, PRAL, and NAE were 58.2 ± 24.3, 9.7 ± 18.4, and 32.1 ± 19.8 mEq/day, respectively. Considering all participants, dietary acid load was significantly, inversely associated with serum bicarbonate, adjusting for age, gender, race, eGFR, body mass index, and diuretic use: −1.2 mEq/L per standard deviation (SD) NEAP (95% confidence interval [CI] −1.8 to −0.6, P P = .0005); −0.7 mEq/L bicarbonate per SD NAE (95% CI −1.2 to −0.1, P = .01). These associations were similar in participants with and without CKD. However, neither NEAP and PRAL nor NAE was significantly associated with SI clamp . Serum bicarbonate was also not significantly associated with SI clamp . Conclusions In CKD, dietary acid load is associated with serum bicarbonate, suggesting that acidosis may be improved by dietary changes, but not with insulin sensitivity.

Chronic kidney disease (CKD) leads to the retention of uremic solutes that disrupt skeletal muscle function1 leading to reduced physical performance and mobility limitation2. Disruption of muscle mitochondrial energetics in CKD may precede the onset of detectable functional limitations. In particular, reduced coupling of ATP production to oxygen consumption (P/O ratio) within mitochondria of skeletal muscle indicates oxidative stress, impaired metabolism, and reduced exercise efficiency3–6. Comprehensive analysis of skeletal muscle mitochondrial energetics in CKD patients has been limited by lack of precise, real-time, non-invasive techniques.

Kidney disease leads to clinically relevant disturbances in glucose and insulin homeostasis, but the pathophysiology in moderate-severe CKD remains incompletely defined. In a cross-sectional study of 59 participants with nondiabetic CKD (mean eGFR =37.6 ml/min per 1.73 m(2)) and 39 healthy control subjects, we quantified insulin sensitivity, clearance, and secretion and glucose tolerance using hyperinsulinemic-euglycemic clamp and intravenous and oral glucose tolerance tests. Participants with CKD had lower insulin sensitivity than participants without CKD (mean[SD] 3.9[2.0] versus 5.0 [2.0] mg/min per µU/ml; P

A rapid ultra-performance liquid chromatography (UPLC) method for the determination of domperidone in the presence of its process impurities and droperidol was developed and validated. The rapid chromatographic separation was achieved using a sub 2 µm Hypersil Zorbax eXtra Densely Bonded C18 column (30 × 4.6 mm, i.d., 1.8 µm). A gradient mobile phase consisting of Solvent A: 0.06 M ammonium acetate and Solvent B: methanol, with a flow rate of 1 mL/min was employed. The column temperature was set at 40°C, and the diode-array detector was set at 280 nm. An injection volume of 3 µL was used. The currently utilized European Pharmacopeia (Eur. Pharm.) method employed by Janssen Pharmaceuticals Ltd was run on a Hypersil Base-Deactivated Silica C18 column (100 × 4.6 mm, i.d., 3 µm) with a run time of 12.5 min. The developed UPLC method, with a run time of 7.5 min was determined to be accurate, precise, specific, robust and highly sensitive according to the International Conference on Harmonization guidelines. The method herein demonstrated a reduction in analysis time of 40%, allowing for a much higher sample throughput. A solvent consumption decrease of over 58% was also observed, which results in a dramatic reduction in running costs for Janssen Pharmaceuticals Ltd.

A rapid liquid chromatographic method was developed for the determination of oxatomide in its finished active pharmaceutical ingredient form and in the presence of its process impurities. The method was developed on a sub 2 mm Hypersil Zorbax XDB C18 column (30 3 4.6 mm, i.d., 1.8 mm). The rapid method employed a gradient mobile phase consisting of solvent A: 0.01 M tetrabutylammonium hydrogen sulfate and 0.5% (w/v) ammonium acetate in water and solvent B: acetonitrile. A flow rate of 2 mL/min was employed with the diode-array detector set at 230 nm. The original method supplied by Janssen Pharmaceuticals Ltd was run on a Thermo Scientific octadecylsilyl silica gel C18 column (100 3 4.6 mm, i.d., 5 mm) with an analysis time of 20 min. The main aim was to substantially reduce the analysis time while maintaining good efficiency. Run-time was reduced to 6.5 min with a total loss in analysis time of 68%. Solvent consumption was also reduced by 68%. Validation according to the International Conference of Harmonization guidelines was undertaken. The parameters examined were accuracy, precision, linearity, selectivity, robustness, limit of detection and limit of quantification; all criteria were met. Sample stability testing was also carried out. Oxatomide proved stable under ambient and 48C temperatures and in the presence of light for up to 24 h.

Received 15 September 2013; revised 16 December 2014 A rapid HPLC method was developed for the simultaneous determination of 10 UV filters found in sunscreen. The following UV filters were analyzed in this method; 2-phenylbenzimidazole-5-sulfonic acid, benzophenone-3, isoamyl p-methoxycinnamate, 4-methylbenzylidene camphor, octocrylene, ethylhexyl dimethyl 4-aminobenzoic acid, ethylhexyl methoxycinnamate, butyl methoxydibenzoylmethane, ethylhexyl salicylate and homosalate. The method was developed on two columns; a Thermo Hypersil C18 BDS, 3 mm column (4.6 3 100 mm) and a Chromolith RP-18e Monolithic column (4.6 3 100 mm). The same mobile phase of ethanol and 1% acetic acid (70:30, v/v) was employed for both columns. The separation of the 10 UV filters was carried out successfully on both columns; the optimal resolution was obtained on the Thermo Scientific Hypersil column in a time frame of 7 min. An isocratic elution utilizing ethanol and acetic acid (70:30, v/v) at a temperature of 358C was employed. The method was applied to a number of commercial samples of sunscreen and lotions and was validated according to International Conference on Harmonisation guidelines for selectivity, linearity, accuracy, precision and robustness. A comparison of the performances of both columns was also carried out.

A simple, rapid ultra-performance liquid chromatography (UPLC) method was developed for the analysis of itraconazole and its associated production impurities. The optimum chromatographic conditions were achieved using an Agilent Zorbax Eclipse XDB C18 column, 1.8 µm (4.6 × 50 mm) installed in a column oven heater utilizing a gradient mobile phase of 0.08M tetrabutylammonium hydrogen sulfate buffer-acetonitrile (80:20, v/v), with ultraviolet detection at 235 nm. An Agilent 1200 RRLC Series was used for the UPLC analysis. UPLC is a technology that greatly reduces analysis time by utilizing columns packed with sub-2 µm particles. The method was validated according to International Conference on Harmonization guidelines with respect to precision, accuracy, linearity, robustness and limits of detection and quantification. All parameters were found to be well within the stated guidelines. The total analysis time was reduced by two-thirds, from over 30 min (the current European Pharmacopeia method) to under 10 min, and the method is applicable for assay and related substance determination. A method utilizing the sub-2 µm column on a conventional high-performance liquid chromatography system was also developed and validated, resulting in substantial time and solvent savings.