Tandem Mass Spectrometry Detection Research Articles

Urinary proteomic pattern in female stress urinary incontinence: a pilot study.

Introduction and hypothesisPrevious studies aiming to identify specific pre-defined urine protein biomarkers for stress urinary incontinence (SUI) have not identified clinically important differences. The hypothesis of our study was that the global distribution of urinary proteins, the proteome, differs between women with and those without SUI.MethodsIn this age-matched case–control study, we compared the urinary proteome of 20 women with SUI and 20 controls. Proteins were identified by applying high-performance liquid chromatography separation and tandem mass spectrometry detection. Data analysis was performed using Mascot 2.4.1 embedded in ProteinScape 3.1.ResultsWe identified 828 different proteins. The concentration of six of those showed a significant difference between urine samples of SUI patients and those of controls (q value < 0.25). Four proteins showed a higher abundance in SUI samples compared with controls: plasma serine protease inhibitor (logFC 1.11), leucine-rich alpha-2-glycoprotein (logFC 3.91), lysosomal alpha-glucosidase (logFC 1.24), and peptidyl-prolyl cis- trans isomerase A (logFC 1.96). We identified two proteins in lower abundance in SUI samples compared with controls: uromodulin (logFC −4.87) and TALPID3 (logFC −1.99).ConclusionsOverexpression of plasma serine protease inhibitor, leucine-rich alpha-2-glycoprotein, lysosomal alpha-glucosidase, and peptidyl-prolyl cis- trans isomerase A, and lower expression of uromodulin and TALPID3, in urine may be associated with female SUI.Electronic supplementary materialThe online version of this article (doi:10.1007/s00192-016-3033-5) contains supplementary material, which is available to authorized users

Development of a high performance liquid chromatography tandem mass spectrometry based analysis for the simultaneous quantification of various Alternaria toxins in wine, vegetable juices and fruit juices

An analytical method based on high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of 12 Alternaria toxins in wine, vegetable juices and fruit juices was developed. Excellent chromatographic performance was demonstrated for tenuazonic acid (TeA) in a multi-analyte method. This comprehensive study is also the first to report the determination of TeA, alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and altenuene (ALT), altertoxin I (ATX-I), altertoxin II (ATX-II), altenuisol (ATL), iso-altenuene (isoALT), altenuic acid III (AA-III) and the AAL toxins TB1 und TB2 in samples from the German market. Several types of HPLC columns were tested for the liquid chromatographic separation of the toxins of interest that widely differ in their polarities. The focus was on gaining suitable retention while avoiding derivatization steps especially for TeA and AA-III. Three atmospheric pressure ionization techniques used with liquid chromatography (electrospray, chemical and photo ionization) were tested to obtain the best selectivity and sensitivity. Samples were diluted with sodium hydrogen carbonate buffer and extracted on a diatomaceous earth solid phase extraction cartridge. Method validation was carried out by using tomato juice, citrus juice and white wine as blank matrices. Limits of detection ranged from 0.10 to 0.59μgL⿿1 and limits of quantification ranged from 0.4⿿3.1μgL⿿1 depending on the toxin and matrix. Recoveries were around 100±9% for all toxins except stemphyltoxin III (STTX-III) and altenusin (ALS) due to instability during sample clean up. Matrix-induced effects leading to ion suppression especially for ATX-I, ATX-II and AA-III were investigated. Relative standard deviations of repeatability (RSDr) and intermediate reproducibility (RSDR) were ⿤9.3 and ⿤17.1, respectively, for the toxins in different matrices at levels of 5 and 30μgL⿿1. Finally, 103 commercially obtained wine and juice samples from the German market in 2015 were analysed. TeA was found most frequently (68% of all analysed samples) in concentrations of up to 60.0μgL⿿1. AOH, AME and TEN were detected in fewer samples (37%, 16% and 30%) at lower concentrations of up to 8.2, 1.5 and 10.3μgL⿿1, respectively. AA-III and ATL were detected for the first time in 3% and 17% of food all samples, in concentrations of up to 6.0μgL⿿1 and 5.9μgL⿿1, respectively.

Two-dimensional liquid chromatography coupled to tandem mass spectrometry for vitamin D metabolite profiling including the C3-epimer-25-monohydroxyvitamin D3

A method based on automated on-line solid phase extraction coupled to two-dimensional liquid chromatography with tandem mass spectrometry detection (SPE-2DLC–MS/MS) is here reported for vitamin D metabolite profiling in human serum with absolute quantitation. Two-dimensional LC was configured with two complementary analytical columns, pentafluorophenyl (PFP) and C18 phases, for determination of 25 hydroxyvitamin D3 epimers and the resting bioactive metabolites of vitamin D (D3 and D2)-25-hydroxyvitamin D2, 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D2 and 24,25-dihydroxyvitamin D3. Quantitative determination was supported on the use of a stable isotopic labelled internal standard for each analyte and the resulting method was validated by analysis of a standard reference material certified by the National Institute of Standards & Technology (NIST-972a) and 5 samples provided by the vitamin D External Quality Assurance Scheme (DEQAS). The limits of detection were between 9 and 90pg/mL for the eight analytes, and precision, expressed as relative standard deviation, was lower than 11.6%. Two-dimensional LC has shown to be the key to discriminate between 25 hydroxyvitamin D3 epimers in a quantitative analysis also involving dihydroxyvitamin D metabolites.

Development of an LC-MS/MS analytical method for the simultaneous measurement of aldehydes from polyunsaturated fatty acids degradation in animal feed.

Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection was developed to measure the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal, and 2,4-decadienal. The developed method was validated according to the criteria and procedure described in international standards. The evaluated parameters were specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters were determined during experiments conducted over three different days with ground Kellogg's® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde, and hexanal can be analyzed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. The analysis of 2,4-nonadienal and 2,4-decadienal can also be performed but in a limited range of concentration and with a limited degree of accuracy. Their recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Urinary levels of bisphenol A, benzophenones and parabens in Tunisian women: A pilot study

Bisphenol A (BPA), benzophenones and parabens are commonly used in the production of polycarbonate plastics, as UV-filters and as antimicrobial preservatives, respectively, and they are thought to exhibit endocrine disrupting properties. Exposure to these compounds remains poorly characterized in developing countries, despite the fact that certain behaviors related to westernization have the potential to influence exposure.The aim of this pilot study was to measure urinary concentrations of BPA, six different benzophenones and four parabens in 34 Tunisian women. In addition, we identified some socio-demographic and dietary predictors of exposure to these compounds. Chemical analyses were carried out by dispersive liquid–liquid microextraction (DLLME) and ultra-high performance liquid chromatography with tandem mass spectrometry detection (UHPLC-MS/MS). Detection frequencies of methylparaben (MP), ethylparaben (EP) and propylparaben (PP) ranged between 67.6 and 94.1%. Butylparaben (BP) was found in 38.2% of the analyzed samples; BPA in 64.7%; and benzophenone-1 (BP-1) and benzophenone-3 (BP-3) were detected in 91.2 and 64.7% of the analyzed samples, respectively. Urinary geometric mean concentrations of MP, EP, PP, and BP were 30.1, 1.4, 2.0 and 0.5ngmL−1, respectively. Geometric mean concentrations of BPA, BP-1, and BP-3 were 0.4, 1.3 and 1.1ngmL−1, respectively.Our results suggest that Tunisian women are widely exposed to BPA, parabens and some benzophenones. Further studies on the general Tunisian population are needed in order to assess the levels of exposure to these compounds and to identify sources of exposure and population groups at higher risk.

Analytical method for 44 pesticide residues in spinach using multi-plug-filtration cleanup based on multiwalled carbon nanotubes with liquid chromatography and tandem mass spectrometry detection.

Spinach is one of the most commonly planted vegetables worldwide. A high chlorophyll content makes spinach a complicated matrix in pesticide residue analysis. In this study, a rapid clean-up method was developed for the analysis of pesticide multi-residues in spinach followed by liquid chromatography with tandem mass spectrometry. A modified QuEChERS method with multiwalled carbon nanotubes and carbon material was adopted in the multi-Plug Filtration Cleanup procedure. This method was validated for 44 representative pesticides spiked at two concentration levels of 10 and 100 μg/kg. The pesticides of different physicochemical properties were registered on spinach in China. The recoveries were between 76 and 114% for major pesticides with relative standard deviations of less than 15%, except for quizalofop-P-ethyl, pyrimethanil, and carbendazim. Matrix-matched calibration curves were performed with the coefficients of determination higher than 0.995 for the studied pesticides for concentration levels of 10-500 μg/kg. The limits of quantitation ranged from 2 to 10 μg/kg. The developed method was successfully applied to determine pesticide residues in Chinese market spinach samples.

Classification of the medicinal plants of the genus Atractylodes using high‐performance liquid chromatography with diode array and tandem mass spectrometry detection combined with multivariate statistical analysis

Analytical methods using high-performance liquid chromatography with diode array and tandem mass spectrometry detection were developed for the discrimination of the rhizomes of four Atractylodes medicinal plants: A. japonica, A. macrocephala, A. chinensis, and A. lancea. A quantitative study was performed, selecting five bioactive components, including atractylenolide I, II, III, eudesma-4(14),7(11)-dien-8-one and atractylodin, on twenty-six Atractylodes samples of various origins. Sample extraction was optimized to sonication with 80% methanol for 40 min at room temperature. High-performance liquid chromatography with diode array detection was established using a C18 column with a water/acetonitrile gradient system at a flow rate of 1.0 mL/min, and the detection wavelength was set at 236 nm. Liquid chromatography with tandem mass spectrometry was applied to certify the reliability of the quantitative results. The developed methods were validated by ensuring specificity, linearity, limit of quantification, accuracy, precision, recovery, robustness, and stability. Results showed that cangzhu contained higher amounts of atractylenolide I and atractylodin than baizhu, and especially atractylodin contents showed the greatest variation between baizhu and cangzhu. Multivariate statistical analysis, such as principal component analysis and hierarchical cluster analysis, were also employed for further classification of the Atractylodes plants. The established method was suitable for quality control of the Atractylodes plants.

Rapid Screening of Antioxidant Anthocyanins in Autochthonous Nero d’Avola Grape Clones by Pre-column DPPH Reaction Coupled to UHPLC-UV/Vis-IT-TOF: a Strategy to Combine Chemical data and Genetic Diversity

Grape is a rich source of bioactive compounds; among them anthocyanins are associated to many healthy properties, possessing a good antioxidant activity. In this work, we developed a fast and simple screening of antioxidant anthocyanins in six Sicilian Nero d’Avola autochthonous grape clones. The method was based on the pre-column reaction with 2,2′-diphenyl-1-picrylhydrazyl radical followed by the rapid separation by ultra high-pressure liquid chromatography coupled with ultraviolet and tandem mass spectrometry detection. Peak areas of antioxidant anthocyanins significantly reduced or even disappeared. The entire method took only 45 min per sample, showing good retention time and peak area repeatability with maximum CV% values ≤0.86 and 6.84, respectively. Samples rich in delphinidin derivatives showed lowest IC50 values, since those compounds possess the highest scavenging ability. The developed setup was less complex than online approaches and faster with respect to conventional high-performance liquid chromatography methods, taking advantage of ultra high-performance conditions, coupled for the first time with pre-column 2,2′-diphenyl-1-picrylhydrazyl assay. The proposed strategy is a valid tool for a rapid screening of antioxidant anthocyanins in grape samples, useful to correlate the genetic diversity with the production of secondary metabolites as well to assess their activity in nutraceutical products rich in anthocyanins.

Characterization of the ultraviolet–visible photoproducts of thiophanate-methyl using high performance liquid chromatography coupled with high resolution tandem mass spectrometry—Detection in grapes and tomatoes

UV–visible irradiation of thiophanate-methyl (TM) led to the formation of nine photoproducts that were characterized by high performance liquid chromatography coupled with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Although carbendazime has been reported in the literature to be the major metabolite and photoproduct of thiophanate-methyl, it was not detected in this study. However, an isomer of carbendazime referred as PP2, which was unambiguously characterized owing to CID experiments, was found in great abundance. Grape berries and cherry tomatoes treated with aqueous solutions of thiophanate-methyl were submitted to irradiation under laboratory conditions. TM and PP2 were detected in both peel and flesh of berries. The ability of TM and PP2 to pass through the fruit skin has been shown to be highly compound and matrix dependent. In vitro bioassays on Vibrio fischeri bacteria showed that the global ecotoxicity of the TM solution increases significantly with the irradiation time. PP2 should likely contribute to this ecotoxicity enhancement since in silico estimations for Daphnia magna provide a LC50 value seven times lower for PP2 than for the parent molecule.

Dual ultrasonic-assisted dispersive liquid–liquid microextraction coupled with microwave-assisted derivatization for simultaneous determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by ultra high performance liquid chromatography–tandem mass spectrometry

This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid–liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4′-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma.

A validated simultaneous quantification method for vonoprazan (TAK-438F) and its 4 metabolites in human plasma by the liquid chromatography-tandem mass spectrometry.

Vonoprazan fumarate (TAK-438) is a potassium-competitive acid blocker which was approved in Japan for a treatment of acid-related diseases. In this study a simple and validated bioanalytical method, which can simultaneously determine vonoprazan (TAK-438F) and its four metabolites (M-I, M-II, M-III and M-IV-Sul) in human plasma, was developed. The method is based on protein precipitation and subsequent ultra-high performance liquid chromatography separation followed by tandem mass spectrometry detection. The mass spectrometric parameters for detection of TAK-438F, M-I, M-III and M-IV-Sul were modified from their optimum values in order to achieve a simultaneous quantification while retaining enough sensitivity and wide dynamic ranges for all the target analytes. The validity and robustness of the method was verified through a validation study as per the regulatory guidance on bioanalytical method validation. The calibration ranges are 0.1-100 ng/mL for TAK-438F and M-III, and 1-1000 ng/mL for M-I, M-II and M-IV-Sul using the 100 μL of human plasma. The total run time per sample is 5 min. The working solution for M-III was recommended to be prepared separately, especially for the long-term use, in order to avoid the instability of M-III in the mixed working solutions, which could cause the high consumption of reference standards. The established method was applied to clinical pharmacokinetic studies and concentrations of all the analytes in human plasma were successfully determined with high reproducibility ensured by incurred sample reanalysis, indicating the suitableness of the established method.

Determination of androgens and progestogens in environmental and biological samples using fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry

Androgens and progestogens are two important groups of endocrine disrupting compounds (EDCs) which are implicated to produce severe detrimental impact over aquatic biota, even at very low concentrations of ngL−1. For this reason, one of the major challenges to analytical chemists is the development of sensitive and selective extraction processes which allow the rapid and green determination of these emerging pollutants at low concentrations in environmental samples. Fabric phase sorptive extraction is a new, highly sensitive, efficient and solvent minimized technique which combine the advantages of sol–gel derived microextraction sorbents and the rich surface chemistry of cellulose fabric substrate. This process has several advantages such as minimum usage of organic solvents, short extraction times, small sample volumes and high analyte preconcentration factors. In this study, an extraction method based on sorptive fabric phase coupled to ultra-high-performance liquid chromatography tandem mass spectrometry detection (FPSE-UHPLC–MS/MS) has been developed for the determination of four progestogens and six androgens in environmental and biological samples. All the parameters involved in the extraction, such as sample volume, extraction and desorption times, desorption solvent volume and sample pH values have been optimized. The developed method provides satisfactory limits of detection (between 1.7 and 264ngL−1), good recoveries and low relative standard deviations (below 10% in tap and osmosis water and below 20% in wastewater and urine). Subsequently, the method was used to analyse tap water, wastewater treated with different processing technologies and urine samples. The concentrations of the detected hormones ranged from 28.3 to 227.3 ngL−1 in water samples and from 1.1 to 3.7μgL−1 in urine samples.

Metabolite profiling of licorice (Glycyrrhiza glabra) from different locations using comprehensive two-dimensional liquid chromatography coupled to diode array and tandem mass spectrometry detection

Profiling of the main metabolites from several licorice (Glycyrrhiza glabra) samples collected at different locations is carried out in this work by using comprehensive two-dimensional liquid chromatography (LC × LC) coupled to diode array (DAD) and mass spectrometry (MS) detectors. The optimized method was based on the application of a HILIC-based separation in the first dimension combined with fast RP-based second dimension separation. This set-up was shown to possess powerful separation capabilities allowing separating as much as 89 different metabolites in a single sample. Identification and grouping of metabolites according to their chemical class were achieved using the DAD, MS and MS/MS data. Triterpene saponins were the most abundant metabolites followed by glycosylated flavanones and chalcones, whereas glycyrrhizic acid, as expected, was confirmed as the main component in all the studied samples. LC × LC-DAD-MS/MS was able to resolve these complex licorice samples providing with specific metabolite profiles to the different licorice samples depending on their geographical origin. Namely, from 19 to 50 specific compounds were exclusively determined in the 2D-chromatograms from the different licorice samples depending on their geographical origin, which can be used as a typical pattern that could potentially be related to their geographical location and authentication.

Investigation of Air-Liquid Interface Rings in Buffer Preparation Vessels: the Role of Slip Agents.

Air-liquid interface rings were observed on the side walls of stainless steel buffer vessels after certain downstream buffer preparations. To investigate the root cause of this issue, multiple analytical techniques have been employed to characterize the chemical composition of air-liquid interface rings. The main components of air-liquid interface rings were determined to be slip agents, which are common additives used in the manufacturing process of thin films. The origin of the slip agents can be traced back to their presence on certain raw material packaging liners. To mitigate this air-liquid interface ring issue, an alternate liner with low slip agent was identified and implemented.

Development and Validation of an LC-MS/MS Method for the Quantification of Agaritine in Mushrooms.

Agaritine, an aromatic hydrazine, is found as a secondary metabolite in mushroom species. It is among others suspected to exhibit genotoxic activity. This publication describes the validation of a method for the quantification of agaritine in mushrooms (i.e., extraction and purification by solid phase extraction) and measurement by liquid chromatography with tandem mass spectrometry detection in positive ionization mode. The results show this method to be selective, accurate, and precise. This method could be used for the quality control of pharmaceutical preparations containing mushrooms.

Bioequivalence Study of Two Formulations That Contain Isotretinoin 20 mg Capsules in Healthy Colombian Volunteers

This is a pharmacokinetic test of two formulations that contain 20 mg of Isotretinoin, with the aim to compare the bioavailability between the Test Product (Isoface® from Procaps Laboratory SA, Colombia) and the Reference Product (Roaccutane® from Catalent Laboratory Germany, Eberbach GMBH, Germany), to declare the bioequivalence between both formulations. An open, crossed study was developed, randomized, of two periods and two sequences, with 40 mg single dose of isotretinoin, on fasting conditions, on 24 healthy male Colombian volunteers; the washout was 14 days in between each period. To present the results, curves of the plasma concentration ratio vs. Time until hour 72 were performed; with the aim to identify the concentration provided by the Test formulation, the basal status of each volunteer was eliminated from the analysis, which was built with 3 former concentrations to the test medicine administration. The analytical method used in this study was high resolution liquid chromatography with tandem mass spectrometry detector, HPLC MS/MS, for plasma Isotretinoin identification and quantification. The main pharmacokinetic parameters for the Test Product vs. the Reference Product were Tmax 2.6 vs. 2.8 h, Cmax 190.5 vs. 186.5 ng/mL for the AUC0-t 3003.8 vs. 2933.5 h*ng/mL and AUC0-∞ 3726.3 vs. 3521.2 h*ng/mL. The confidence interval calculation of data with logarithmic transformation, showed confidence intervals for the variables Tmax, Cmax, AUCo-t and AUCo-∞, with values between 80-125; values approved by the FDA and EMA European Medicines Agency, in their Bioavailability and Bioequivalence Guides, to accept the Bioequivalence hypothesis between the two formulations in study, and thereby declare Bioequivalence and interchange ability of the Test Product from Procaps Laboratory, with the Reference Product from Roche Laboratory.

Analysis of Veterinary Drug and Pesticide Residues Using the Ethyl Acetate Multiclass/Multiresidue Method in Milk by Liquid Chromatography-Tandem Mass Spectrometry.

A rapid and simple multiclass, ethyl acetate (EtOAc) multiresidue method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) detection was developed for the determination and quantification of 26 veterinary drugs and 187 total pesticide residues in milk. Sample preparation was a simple procedure based on liquid–liquid extraction with ethyl acetate containing 0.1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in ethyl acetate with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil X-Terra C18 column with acetic acid in methanol and water gradient. The repeatability and reproducibility were in the range of 2 to 13% and 6 to 16%, respectively. The average recoveries ranged from 75 to 120% with the RSD (n = 18). The developed method was validated according to the criteria set in Commission Decision 2002/657/EC and SANTE/11945/2015. The validated methodology represents a fast and cheap alternative for the simultaneous analysis of veterinary drug and pesticide residues which can be easily extended to other compounds and matrices.

Bile acids synthesis decreases after laparoscopic sleeve gastrectomy

BackgroundBariatric surgery is the most effective treatment alternative in morbid obesity. The mechanisms contributing to these benefits remain poorly understood. Bile acids (BAs) are mediators of different regulatory functions in glucose and cholesterol homeostasis and energy expenditure. Recent evidence suggests that BAs are critically important for the beneficial effects of sleeve gastrectomy (SG). ObjectivesThe aim of this study was to evaluate the effect of SG on BA synthesis. SettingUniversity Hospital. Santiago, Chile. MethodsObese patients were evaluated before and after SG (1, 3, 6, and 12 months). BA synthesis was evaluated through the serum marker, 7 α-hydroxy-4-cholesten-3-one (C4). Primary and secondary BA and C4 were determined by high performance liquid chromatography coupled with tandem mass spectrometry detection (HPLC-MS/MS). ResultsFrom June 2013 to January 2014, 19 patients (age 37.6±7.8 years; BMI 35.8±3.5 kg/m2; 79% female) were included in this study. Mean weight loss at 1, 3, 6, and 12 months was 11.3, 17.5, 23.6, and 25.4 kg, respectively, equivalent to 11.8, 18.6, 24.8, and 26.9 of total body water percentage (%TBW) (P<.0001), respectively and 43.2, 68.2, 91, and 98.8 of percentage of excess weight loss (%EWL), respectively (P<.001). Serum C4 levels at baseline, 1, 3, 6, and 12 months were 23.4±21.1, 4.9±8.2, 8.7±12.1, 13.8±12.9, and 18.8±16.8 ng/mL (P<.0001), respectively. Fibroblast growth factor 19 (FGF19) levels at baseline, 1, 3, 6, and 12 months were 71±33.3, 130.5±66.2, 117.8±57.2, 134.6±91.7, and 124.3±85.9 pg/mL (P = .019), respectively. ConclusionSerum levels of C4 decrease after SG, indicating a reduction in the synthesis of BA. FGF19 may play a role in decreasing BA synthesis. Further studies are necessary to characterize the effect of bariatric surgery on BA homeostasis.

CCN5/WISP2 Protein Stimulates Pancreatic Islet Cell Proliferation and Survival Through Sustained Activation of AKT Kinase and the Expression of Specific Target Genes

1000 international units (IU) and less, whereas in higher doses it is considered an ethical pharmaceutical. Patients and physicians may rely upon the OTC preparations to manage metabolic bone disease and to optimize response to osteoporosis pharmaceuticals. Assurance of cholecalciferol content in commercial cholecalciferol preparations is of great importance to patient outcomes. OTC and ethical pharmaceutical preparations are handled differently with regulatory authorities. OTC preparations are assigned an NPN (natural products number) based on parameters which differ from ethical pharmaceutical preparations which are assigned a DIN (drug identification number). We assayed the cholecalciferol content of 22 supplements available as OTC pharmaceutical products obtained from retail pharmacies in Canada. We used HPLC with tandem mass spectrometry detection. Tablets were first pulverized in a mortar and pestle, then extracted with methanol. After centrifuging, the methanol extract was applied to the HPLC column and run with appropriate standards. Mean cholecalciferol content of the OTC pharmaceuticals was 55.4 % of the declared label amount (range 7 to 119%). 77% of the preparations contained less than 80% of the label amount. (Table) We conclude that OTC cholecalciferol preparations are generally at less than label indicated potency. Prescription cholecalciferol preparations aremore likely to contain the label amount of vitamin. This information is important to patients and prescribing physicians; consideration of more stringent monitoring of OTC preparations by health authorities is warranted.

Simultaneous quantification of picfeltarraenins IA and IB in rat plasma by UPLC–MS/MS: Application to a pharmacokinetic study

A simple and rapid quantitative UPLC-MS/MS method for simultaneous determination of picfeltarraenins IA and IB in rat plasma was developed and validated in accordance with the US FDA Bioanalytical Guidance (2001). Analytes were extracted from rat plasma by using methanol and separated on Agilent ZORBAX SB-C18 (50mm×2.1mm, 1.8μm) column by using a mobile phase composed of methanol and water (70:30, v/v). Eluents were monitored by ESI tandem mass spectrometry detection with SRM mode using ion transitions m/z 785.4→639.5, m/z 815.5→669.5, and m/z 763.5→455.3 for picfeltarraenin IA, picfeltarraenin IB, and internal standard, respectively. The method was validated over the linear range of 11.5-1150ng/mL and 13.0-1300ng/mL. The developed analytical method was applied to support a pharmacokinetic study on simultaneous estimation of picfeltarraenins IA and IB in rats.