Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 51
Filter
1.
Osteoporos Int ; 28(6): 1995-2002, 2017 06.
Article in English | MEDLINE | ID: mdl-28299378

ABSTRACT

A first intravenous dose of bisphosphonates may be associated with an acute-phase response (APR). In bisphosphonate-naïve women with postmenopausal osteoporosis, the characteristics and frequency of APR may differ by compound. Prior bisphosphonate exposure was predictive of APR risk and severity. INTRODUCTION: Intravenous (IV) administration of bisphosphonates (BP), such as zoledronate (ZOL) and ibandronate (IBN), may be associated with an APR. The characteristics of APR may differ by compound. The aim of the present study was to evaluate the characteristics of APR (rates, signs and symptoms, severity), in the absence of any preventive measure, after a first IV application of ZOL or IBN in patients naïve or previously exposed to BP in a real-world clinical setting. METHODS: This is an open-label prospective exploratory study with two cohorts of consecutive postmenopausal women with osteoporosis treated with either IV ZOL or IBN at the Department of Osteoporosis of the University Hospital of Berne, Switzerland. RESULTS: Intravenous BP was administered to 725 women (411 ZOL and 314 IBN). Prior oral or IV BP use was less frequent in the ZOL group (61.8 vs. 71.7%, p = 0.005). In total, 301 women (41.5%) reported the presence of one or more signs or symptoms of APR with rates for ZOL and IBN of 47.7 and 33.4%, respectively (p < 0.001). Corresponding APR rates in the subgroup of BP-naïve patients were 55.6 and 32.4%, respectively (p < 0.001). The leading APR clinical sign was the presence of post-dose myalgia or arthralgia (68.1%). Prior BP exposure was predictive of both APR risk and severity, and lower serum 25-hydroxy vitamin D (25(OH)D) levels were possibly predictive of severity. CONCLUSIONS: In a real-world setting, APR rates with ZOL and IBN may be higher than reported in randomised controlled trials and may differ by compound, prior BP exposure, and serum 25(OH)D levels.


Subject(s)
Acute-Phase Reaction/chemically induced , Bone Density Conservation Agents/adverse effects , Diphosphonates/adverse effects , Imidazoles/adverse effects , Osteoporosis, Postmenopausal/drug therapy , Aged , Bone Density Conservation Agents/administration & dosage , Bone Density Conservation Agents/therapeutic use , Diphosphonates/administration & dosage , Diphosphonates/therapeutic use , Female , Humans , Ibandronic Acid , Imidazoles/administration & dosage , Imidazoles/therapeutic use , Infusions, Intravenous , Middle Aged , Prospective Studies , Risk Factors , Severity of Illness Index , Zoledronic Acid
2.
Anal Bioanal Chem ; 403(6): 1731-41, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22538775

ABSTRACT

The determination of pesticides in food products is an essential issue to guarantee food safety and minimise health risks of consumers. A protocol based on membrane-assisted solvent extraction and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) that allows the determination of 18 pesticides in red wine at minimum labour effort for sample preparation was developed and validated. Ten millilitres of wine were extracted using 100 µL of toluene filled in a non-porous polyethylene membrane bag which is immersed in the wine sample. After 150 min extraction under stirring, an aliquot of the extraction solution is analysed using HPLC-MS/MS. The limits of quantification ranged from 3 ng/L for Pirimicarb to 1.33 µg/L for Imidacloprid. Quantification by matrix-matched calibration provided relative standard deviations ≤16 % for most of the target pesticides. The linearity of calibration was given over three to four orders of magnitude, which enables the reliable measurement of a broad range of pesticide concentrations, and for each target pesticide, the sensitivity of the protocol meets the maximum residue levels set by legislations at least for wine grapes. Good agreement of results was found when the new method was compared with a standard liquid-liquid extraction protocol. In five wine samples analysed, Carbendazim and Metalaxyl were determined at micrograms per litre concentrations, even in some of the organic wines. Tebuconazol and Cyprodinitril were determined at lower abundance and concentration, followed by Spiroxamin and Diuron.


Subject(s)
Chromatography, High Pressure Liquid/methods , Membranes, Artificial , Pesticide Residues/analysis , Solvents/chemistry , Tandem Mass Spectrometry/methods , Wine/analysis , Hydrogen-Ion Concentration
3.
Rev. chil. radiol ; 14(2): 83-93, 2008. graf, tab
Article in Spanish | LILACS | ID: lil-517427

ABSTRACT

Purpose: Quantification of the impact of a PACS/RIS-integrated speech recognition system (SRS) on the time expenditure for radiology reporting and on hospital-wide report availability (RA) in a university institution. Material and methods: In a prospective pilot study, the following parameters were assessed for 669 radiographic examinations (CR): 1. time requirement per report dictation (TED: dictation time (s)/number of images (examination) x number of words (report)) with either a combination of PACS/ tape-based dictation (TD: analog dictation device/ minicassette/transcription) or PACS/RIS/speech recognition system(RR: remote recognition/transcription and OR: online recognition/self-correction by radiologist), respectively, and 2. the ReportTur-naround Time (RTT) as the time interval from the entry of the first image into the PACS to the available RIS/HIS report. Two equal time periods were chosen retrospectively from the RIS database: 11/2002-2/2003 (only TD) and 11/2003-2/2004 (only RR or OR with speech recognition system (SRS)). The midterm (> 24 h, 24 h intervals) and short-term (< 24 h, 1 h intervals) RA after examination completion were calculated for all modalities and for CR, CT, MR and XA/DS separately. The relative increase in the mid-term RA (RIMRA: related to total number of examinations in each time period) and increase in the short-term RA (ISRA: ratio of available reports during the 1st to 24th hour) were calculated. Results: Prospectively there was a significant difference between TD/RR/OR (n = 151/257/261) regarding mean TED (0.44/0.54/0.62 s (per word and image)) and mean RTT.


Objetivo: Cuantificar la repercusión de un sistema de reconocimiento del habla integrado en un PACS/RIS en el tiempo invertido en los informes radiológicos y su disponibilidad en una Clínica Universitaria. Material y métodos: Estudio piloto prospectivo; en 669 radiografías se registró el tiempo invertido por dictado con cinta y sistemas PACS/RIS de reconocimiento (dictado por lotes o dictado en línea) y el Report Turnaround Time, intervalo de tiempo desde la introducción de imagen en PACS hasta tener informe disponible en RIS/CIS. En análisis retrospectivo de base de datos de RIS se estudió 11/2002-02/2003 y 11/2003-02/2004. Se calculó la media y el aumento relativo de la disponibilidad de informes a mediano y corto plazo tras la finalización del estudio. Resultados: Se observaron importantes diferencias en el tiempo invertido para cada modalidad (0,44/0,54/0,62 s por palabra e imagen) y del RTT medio (10,47/6,65/1,27 h). Se evaluaron retrospectivamente 37.898/39.680 informes de los períodos mencionados. En CR/TC, se observó un aumento medio del 20 por ciento en la disponibilidad de informes a corto plazo y en todas las modalidades fue más del triple en las primeras 24 h. En el caso de CR/TC/RM, el primer día hubo un aumento máximo de la disponibilidad a mediano plazo (factor 3,1/5,8/4,0) y en el caso de XA/DS, en el segundo día (factor 2,0). Conclusión: Cuando se utiliza un sistema de reconocimiento del habla se modifica el flujo de trabajo y se invierte inicialmente más tiempo para la elaboración de informes. Los sistemas de reconocimiento integrados en PACS/RIS mejoran considerablemente la disponibilidad de los informes a corto y mediano plazo, redundando en la calidad de la atención de los pacientes.


Subject(s)
Humans , Radiology , Medical Records Systems, Computerized/statistics & numerical data , Radiology Information Systems/statistics & numerical data , Speech Recognition Software/statistics & numerical data , Pilot Projects , Prospective Studies , Radiology Department, Hospital/statistics & numerical data , Time Factors
4.
J Chromatogr A ; 1124(1-2): 196-204, 2006 Aug 18.
Article in English | MEDLINE | ID: mdl-16870197

ABSTRACT

Selected polycyclic musk compounds and drugs were extracted from water samples by membrane-assisted micro liquid-liquid extraction. The two-phase extraction system consisted of polyethylene membrane bags filled with an organic solvent. Chloroform proved to be most suited as acceptor phase to extract caffeine, Galaxolide, Tonalide, phenazone and carbamazepine from aqueous samples. The compounds were enriched from 50 mL sample into a volume of 500 microL of chloroform. Gas chromatography-mass spectrometry (GC-MS) was applied for analysis. The extraction procedure was optimised in regard to membrane material, extraction time and temperature. The evaluation of the entire analysis protocol found limits of detection that ranged from 20 to 200 ng/L. The linear range of calibration covered one magnitude with standard deviations between 4 and 12%. Method comparison with standard analysis techniques such as solid-phase extraction (SPE) combined with GC-MS as well as LC-MS-MS confirmed this method as an easy and reliable protocol, even for the monitoring of matrix-loaded wastewater. The analysis of real samples established the feasibility of the technique.


Subject(s)
Chromatography, Liquid/methods , Gas Chromatography-Mass Spectrometry/methods , Pharmaceutical Preparations/analysis , Polycyclic Compounds/analysis , Water Pollutants, Chemical/analysis , Calibration
5.
Rofo ; 178(4): 400-9, 2006 Apr.
Article in German | MEDLINE | ID: mdl-16607588

ABSTRACT

PURPOSE: Quantification of the impact of a PACS/RIS-integrated speech recognition system (SRS) on the time expenditure for radiology reporting and on hospital-wide report availability (RA) in a university institution. MATERIAL AND METHODS: In a prospective pilot study, the following parameters were assessed for 669 radiographic examinations (CR): 1. time requirement per report dictation (TED: dictation time (s)/number of images [examination] x number of words [report]) with either a combination of PACS/tape-based dictation (TD: analog dictation device/mini-cassette/transcription) or PACS/RIS/speech recognition system (RR: remote recognition/transcription and OR: online recognition/self-correction by radiologist), respectively, and 2. the Report Turnaround Time (RTT) as the time interval from the entry of the first image into the PACS to the available RIS/HIS report. Two equal time periods were chosen retrospectively from the RIS database: 11/2002 - 2/2003 (only TD) and 11/2003 - 2/2004 (only RR or OR with speech recognition system [SRS]). The mid-term (> or = 24 h, 24 h intervals) and short-term (< 24 h, 1 h intervals) RA after examination completion were calculated for all modalities and for CR, CT, MR and XA/DS separately. The relative increase in the mid-term RA (RIMRA: related to total number of examinations in each time period) and increase in the short-term RA (ISRA: ratio of available reports during the 1st to 24th hour) were calculated. RESULTS: Prospectively, there was a significant difference between TD/RR/OR (n = 151/257/261) regarding mean TED (0.44/0.54/0.62 s [per word and image]) and mean RTT (10.47/6.65/1.27 h), respectively. Retrospectively, 37 898/39 680 reports were computed from the RIS database for the time periods of 11/2002 - 2/2003 and 11/2003 - 2/2004. For CR/CT there was a shift of the short-term RA to the first 6 hours after examination completion (mean cumulative RA 20 % higher) with a more than three-fold increase in the total number of available reports within 24 hours (all modalities). The RIMRA for CR/CT/MR was 3.1/5.8/4.0 in the first 24 hours, and 2.0 for XA/DS in the second 24-hour interval. CONCLUSION: In comparison to tape-based dictation, an SRS results in a significantly higher primary time expenditure and a modified report dictation workflow. In a university institution, a PACS/RIS-integrated SRS achieves a marked improvement in both short- and mid-term RA which eventually results in an improvement in patient care.


Subject(s)
Efficiency, Organizational/statistics & numerical data , Radiology Department, Hospital/statistics & numerical data , Radiology Information Systems/statistics & numerical data , Speech Recognition Software/statistics & numerical data , Germany , Hospitals, University/statistics & numerical data , Humans , Tape Recording/statistics & numerical data , Technology Assessment, Biomedical , Time Factors
6.
J Chromatogr A ; 1071(1-2): 155-62, 2005 Apr 15.
Article in English | MEDLINE | ID: mdl-15865188

ABSTRACT

An optimized method using stir bar sorptive extraction (SBSE) for the determination of 25 polychlorinated biphenyls (PCBs) from water samples among them three of the most toxic coplanar PCBs (PCB 77, PCB 126 and PCB 169) was developed. Since the investigated PCBs comprise all steps of chlorination (from PCB 1 as monochlorobiphenyl to PCB 209 as decachlorobiphenyl) the results should be representative for the total class of the 209 PCB congeners. For 8 ml spiked water samples with 2 ml methanol addition and 2 h exposure time of stir bars recoveries between 28% (PCB 209) and 93% (PCB 1, PCB 52, PCB 77) were found. Detection limits between 0.05 ng/l and 0.15 ng/l were calculated for the combination of SBSE and thermodesorption-GC/MS. The procedure was applied to the investigation of groundwater and river water samples from the industrial region of Bitterfeld northern Leipzig, Germany.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Polychlorinated Biphenyls/analysis , Water Pollutants, Chemical/analysis , Reference Standards , Sensitivity and Specificity
7.
J Chromatogr A ; 1071(1-2): 163-9, 2005 Apr 15.
Article in English | MEDLINE | ID: mdl-15865189

ABSTRACT

A simple and inexpensive method for sorptive extraction of phenols from water samples is presented. A polydimethyl siloxane (PDMS) stir bar (Twister) is used as an extraction medium for derivatized phenols, which is thermally desorbed and analyzed by gas chromatography-mass spectrometry (GC-MS). Its performance was illustrated and evaluated for the enrichment of microg l(-1) to ng l(-1) of phenol and selected chlorophenols in water samples. The method showed good linearity, recoveries and blank levels, as well as advantages such as sensitivity, simplicity, low cost and high feasibility, being successfully applied for the analysis of phenolic compounds in natural water samples.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Phenols/analysis , Water Pollutants, Chemical/analysis , Calibration , Fresh Water
10.
Article in English | MEDLINE | ID: mdl-15081925

ABSTRACT

A new simple and rapid method for analysing Ochratoxin A (OTA) in small volumes of human blood serum using capillary zone electrophoresis coupled to laser-induced fluorescence is described. The clean-up procedure solely consists of a double extraction step. To improve the reproducibility of migration times and quantification, two internal standards were used. The limit of detection was 0.55 ng/ml, with a linear range of 1-100 ng/ml of OTA in spiked human blood serum. The method is used to rapidly screen suspected patients.


Subject(s)
Mycotoxins/blood , Ochratoxins/blood , Humans , Reference Standards , Reproducibility of Results , Sensitivity and Specificity
11.
Science ; 304(5668): 261-5, 2004 Apr 09.
Article in English | MEDLINE | ID: mdl-15073371

ABSTRACT

We have developed a chemical ionization mass spectrometry technique for precise in situ measurements of hydrochloric acid (HCl) from a high-altitude aircraft. In measurements at subtropical latitudes, minimum HCl values found in the upper troposphere (UT) were often near or below the detection limit of the measurements (0.005 parts per billion by volume), indicating that background HCl values are much lower than a global mean estimate. However, significant abundances of HCl were observed in many UT air parcels, as a result of stratosphere-to-troposphere transport events. We developed a method for diagnosing the amount of stratospheric ozone in these UT parcels using the compact linear correlation of HCl with ozone found throughout the lower stratosphere (LS). Expanded use of this method will lead to improved quantification of cross-tropopause transport events and validation of global chemical transport models.

12.
J Chromatogr A ; 1025(1): 11-6, 2004 Jan 30.
Article in English | MEDLINE | ID: mdl-14753665

ABSTRACT

Short-term solid-phase microextraction (SPME) was performed to test a recently proposed semi-empirical model for the prediction of concentrations of analyte in water samples from the fibre-extracted mass without further calibration. The mass uptake rates obtained for benzene, toluene, ethylbenzene and p-xylene (BTEX) differ considerably from the before published, showing that interfibre comparability is a serious issue. The relative prediction errors are between -55% for benzene and +82% for p-dichlorobenzene under optimal conditions, i.e. they are by an order of magnitude higher than originally published. A sensitivity analysis shows the dominant influence of the estimated thickness of the diffusional boundary layer around the fibre on the concentration predicted. Empirical modification of the model equation for this parameter yields satisfactory results under the conditions tested for both BTEX and the selected chlorobenzenes.


Subject(s)
Benzene Derivatives/isolation & purification , Benzene/isolation & purification , Calibration , Chlorobenzenes/isolation & purification , Toluene/isolation & purification , Xylenes/isolation & purification , Diffusion , Sensitivity and Specificity
13.
J Chromatogr A ; 1025(1): 17-26, 2004 Jan 30.
Article in English | MEDLINE | ID: mdl-14753666

ABSTRACT

A novel, simple and inexpensive approach to absorptive extraction of organic compounds from environmental samples is presented. It consists of a polydimethylsiloxane rod used as an extraction media, enriched with analytes during shaking, then thermally desorbed and analyzed by GC-MS. Its performance was illustrated and evaluated for the enrichment of sub- to ng/l of selected chlorinated compounds (chlorobenzenes and polychlorinated biphenyls) in water samples. The new approach was compared to the stir bar sorptive extraction performance. A natural ground water sample from Bitterfeld, Germany, was also extracted using both methods, showing good agreement. The proposed approach presented good linearity, high sensitivity, good blank levels and recoveries comparable to stir bars, together with advantages such as simplicity, lower cost and higher feasibility.


Subject(s)
Dimethylpolysiloxanes/isolation & purification , Gas Chromatography-Mass Spectrometry/methods , Organic Chemicals/analysis , Silicones/isolation & purification , Water Pollutants, Chemical/analysis , Reproducibility of Results , Sensitivity and Specificity
14.
Science ; 303(5657): 516-20, 2004 Jan 23.
Article in English | MEDLINE | ID: mdl-14739457

ABSTRACT

In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles (Delta-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Delta-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Delta-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.

15.
J Chromatogr A ; 1020(2): 153-60, 2003 Dec 12.
Article in English | MEDLINE | ID: mdl-14661740

ABSTRACT

Membrane-assisted solvent extraction was applied to the determination of polychlorinated biphenyls (PCBs) in aqueous samples. The apparatus of membrane-assisted solvent extraction consisted of a 20 ml headspace vial which was filled with 15 ml of the aqueous sample. The membrane bag was placed into the vial and the extraction took place in an agitator. After extraction, the analytes were transferred into the inlet of a gas chromatograph by large volume injection. A mass-selective detector was used. The whole procedure was fully automated. The work included optimization of the extraction conditions (stirring rate and extraction time) and the influence of matrix effects like salt addition and the presence of organic solvents was studied. Calibration was performed using injection volumes of 100 and 400 microl. Several parameters like linearity and reproducibility of the procedure were determined. At optimized conditions detection limits in the ng/l range were achieved. The effectiveness of the method towards real samples was tested by analyzing river water, white wine and apple juice.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Polychlorinated Biphenyls/analysis , Water Pollutants, Chemical/analysis , Membranes, Artificial , Reproducibility of Results , Sensitivity and Specificity
16.
J Chromatogr A ; 999(1-2): 35-42, 2003 May 30.
Article in English | MEDLINE | ID: mdl-12885049

ABSTRACT

Fibre coating-water distribution constants (Kfw) of more hydrophobic chemicals were determined with six different solid-phase microextraction fibre types (including a polyoctylmethylsiloxane (C8) prototype) by fibre exposure to agitated large-volume water samples lasting several days. The results obtained are comparable with Kfw values obtained under dynamic conditions. Octanol-water partition coefficients (Kow) were measured with the mixture of distributing substances to examine log Kfw-log Kow relationships based on a consistent dataset. Kfw values obtained with liquid polymer fibre coatings correlate reasonably well with the hydrophobicity of the test compounds (with decreasing sensitivity in the following order: 7 microm polydimethylsiloxane (PDMS)>100 microm PDMS>C8>polyacrylate) whereas this is not the case with the PDMS-divinylbenzene (DVB) and Carbowax-DVB fibres, partially porous coatings which provide the highest Kfw values for all substances tested.


Subject(s)
Octanols/chemistry , Organic Chemicals/analysis , Water/chemistry , Sensitivity and Specificity
17.
Anal Bioanal Chem ; 376(1): 53-60, 2003 May.
Article in English | MEDLINE | ID: mdl-12734618

ABSTRACT

A new one-step cleanup procedure, based on size-exclusion chromatography (SEC), usable for the extracts from accelerated solvent extraction (ASE), Soxhlet extraction, or ultrasonic extraction (USE), is described. The method is suitable for the determination of polycyclic aromatic hydrocarbons (PAHs), especially from very complicated plant matrices (e.g. pine needles, deciduous leaves, mosses). The main improvement compared with previous conventional procedures is that analyte peaks barely overlap with matrix peaks in the chromatograms and that it is a very rapid and simple one-step procedure with clearly improved analytical performance. Essential advantages of this SEC procedure are the sharper GC-MS chromatograms for the PAH fraction at retention times between 9.2 and 12.0 min, distinctly separated substance peaks resulting in better analysis, shorter running times, and lower solvent consumption.


Subject(s)
Acer/chemistry , Chromatography, Gel/methods , Pinus/chemistry , Polycyclic Aromatic Hydrocarbons/analysis , Gas Chromatography-Mass Spectrometry , Plant Leaves/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Polycyclic Aromatic Hydrocarbons/isolation & purification , Solvents , Time Factors
18.
J Chromatogr A ; 988(1): 41-51, 2003 Feb 21.
Article in English | MEDLINE | ID: mdl-12647820

ABSTRACT

To enable high sample throughput, an automated solid-phase microextraction (SPME) method coupled with GC-MS for the trace analysis of technical nonylphenol, bisphenol A and 17alpha-ethinylestradiol was developed. The extraction performance of different SPME fibre coatings was examined, with polyacrylate proving most suitable. Although study of the extraction time showed that the analytes have not reached equilibrium after 3 h, as a compromise an extraction time of 1 h was applied in all the experiments with detection limits between 0.04 and 1 microg l(-1) for wastewater effluent. The mean reproducibility of the technique is 8% RSD. Carry-over effects are negligible. The linearity of calibration curves ranges over three orders of magnitude. The method was tested for determining the analytes in influents and effluents of constructed wetland plants and in model wastewater used in laboratory experiments.


Subject(s)
Ethinyl Estradiol/analysis , Gas Chromatography-Mass Spectrometry/methods , Phenols/analysis , Water Pollutants, Chemical/analysis , Benzhydryl Compounds , Calibration , Hydrogen-Ion Concentration , Reproducibility of Results , Sensitivity and Specificity , Sodium Chloride
20.
J Chromatogr A ; 968(1-2): 171-6, 2002 Aug 30.
Article in English | MEDLINE | ID: mdl-12236501

ABSTRACT

The suitability of using metal-loaded sorbents for solid-phase extraction to enrich organic sulfur compounds from water samples was studied. To test the retention behavior of a number of sulfides, thiols and methylthiophosphates, a cation-exchanger was loaded with various metal ions. The elution behavior of sulfur compounds was investigated with different solvents. A combination of Pb2+-modified cation-exchanger as sorbent and CS2 (1%, v/v) in toluene proved to be the most suitable approach for the given problem. Using GC with a pulsed flame photometric detector yielded detection limits of between 0.6 and 2.9 microg/l. The results showed good reproducibility with relative standard deviations of 2-11%.


Subject(s)
Cation Exchange Resins , Chromatography, Gas/methods , Phosphates/analysis , Sulfhydryl Compounds/analysis , Sulfides/analysis , Water Pollutants, Chemical/analysis , Calibration , Metals , Reproducibility of Results
SELECTION OF CITATIONS
SEARCH DETAIL
...