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1.
J Anal Appl Pyrolysis ; 162: 105447, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35068626

RESUMO

The use of quaternary ammonium compounds (QACs) as disinfectants has increased tremendously in the COVID-10 pandemic to inactivate Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV2). Dialkyldimethylammonium halides represent a frequently used type among QACs. Different halide anions, each ionically linked to the same quaternary ammonium cation, show clear differences in biocidal activity, toxicity and allergic potential. Likewise, the alkyl chain length at the ammonium cation induces different biocidal efficacy and toxicology. Therefore, the object of this research was to develop a rapid and reliable method for the detection of ammonium cation and halide anion in a single analytical run. For that purpose, a gas chromatography mass spectrometry (GC/MS) method was developed for QACs of the dialkyldimethylammonium type. Pyrolytic conversion of the QACs in the injector port of the gas chromatograph into volatile molecule species allows fast and reliable subsequent GC/MS analysis. The developed method is suited for the determination of both the quaternary ammonium cation and the corresponding halide anion in a single gas chromatographic run. The application of this method to bulk material and standard material of explicitly specified didecyldimethylammonium chloride revealed deviations from the manufacturer's specifications in a range up to four-fifths. Furthermore, didecyldimethylammonium chloride was detected in a disinfectant that does not comply with the labeling requirement for biocidal ingredients. With the method presented, results can be obtained for disinfectants with minimum effort within seven minutes.

2.
Anal Bioanal Chem ; 413(4): 1091-1098, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33244685

RESUMO

Recycling will be of increasing importance in the future, especially for plastic packaging waste mainly consisting of polyolefins. One major problem of recyclates comprises impurities which can have a significant negative impact on future product properties. Polyamide 6 can be found widely as contaminant in recycled polyolefins, leading to a need of quantification methods thereof. In this paper, a method development for the quantitative analysis of polyamide 6 is presented based on analysing ε-caprolactam and related cyclic oligomers as marker compounds in model recyclates of high- and low-density polyethylene and polypropylene compounded with low amounts of polyamide 6. For the method development and tentative identification of the different cyclic compounds, a HPLC-QTOF-MS was used and it was possible to detect six different compounds, ε-caprolactam and the corresponding cyclic di- to hexamer. The quantification was performed with a HPLC-QQQ-MS, equipped with a HILIC column, after sample preparation via microwave-assisted extraction. It could be shown that a good linearity from 0.2 up to 5 wt% polyamide 6 in the different polyolefins can be achieved. The cyclic trimer and tetramer show a low limit of quantification and are therefore well-suited for the quantification, whereas the other cyclic compounds can be then used as qualifiers to avoid false positives. To guarantee the applicability of the method, six real recyclate materials were analysed, whereby in three of them low amounts of polyamide 6 could be detected. Graphical abstract.

3.
J Pers Med ; 10(4)2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353026

RESUMO

Targeting oncogenic fusion-genes in pediatric high-grade gliomas (pHGG) with entrectinib has emerged as a highly promising therapeutic approach. Despite ongoing clinical studies, to date, no reports on the treatment of cerebrospinal fluid (CSF) disseminated fusion-positive pHGG exist. Moreover, clinically important information of combination with other treatment modalities such as intrathecal therapy, radiotherapy and other targeted agents is missing. We report on our clinical experience of entrectinib therapy in two CSF disseminated ROS1/NTRK-fusion-positive pHGG cases. Combination of entrectinib with radiotherapy or intrathecal chemotherapy appears to be safe and has the potential to act synergistically with entrectinib treatment. In addition, we demonstrate CSF penetrance of entrectinib for the first time in patient samples suggesting target engagement even upon CSF dissemination. Moreover, in vitro analyses of two novel cell models derived from one case with NTRK-fusion revealed that combination therapy with either a MEK (trametinib) or a CDK4/6 (abemaciclib) inhibitor synergistically enhances entrectinib anticancer effects. In summary, our comprehensive study, including clinical experience, CSF penetrance and in vitro data on entrectinib therapy of NTRK/ROS1-fusion-positive pHGG, provides essential clinical and preclinical insights into the multimodal treatment of these highly aggressive tumors. Our data suggest that combined inhibition of NTRK/ROS1 and other therapeutic vulnerabilities enhances the antitumor effect, which should be followed-up in further preclinical and clinical studies.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32738523

RESUMO

A typical lipidomics approach aims at the simultaneous analysis of a multitude of lipid species from different lipid classes with highest possible sensitivity for all target lipids. Efficient extraction of lipids from the biological matrix is a crucial step in the analytical workflow. Whereas numerous applications of classical and more recently published extraction methods have been reported for blood serum or plasma samples, very little is known about the applicability of these methods for cerebrospinal fluid (CSF). CSF though represents a highly interesting biofluid for the investigation of neurological disorders, such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, or brain cancer. Since CSF comprises substantially lower endogenous lipid concentrations compared to serum or plasma, the use of highly efficient extraction methods is of utmost importance. In addition, literature on lipid extraction methods is often inconsistent in terms of methodological parameters like temperature, mixing times, or the number of repeated extraction cycles. In this study, four liquid-liquid extraction methods (Folch, Bligh & Dyer, MTBE and BUME) and one protein precipitation method (MMC method) were evaluated using a pooled CSF sample, followed by the investigation of key process parameters (temperature and mixing times) and modifications of the most promising methods, in order to achieve a broad coverage of lipid classes as well as high recoveries and repeatabilities. A modified Folch method turned out as most suitable for the efficient extraction of a broad range of lipid classes from CSF including glycerophospholipids, glycerolipids and sphingolipids. In addition, using cooled solvents and equipment was shown to significantly improve lipid extraction efficiencies. Mixing times should be thoroughly optimized for the lipid classes of interest in order to achieve high recoveries without lipid degradation due to unnecessarily long mixing. Finally, acidification led to improved extraction efficiency for acidic glycerophospholipids.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lipidômica/métodos , Lipídeos/líquido cefalorraquidiano , Lipídeos/isolamento & purificação , Humanos , Extração Líquido-Líquido , Espectrometria de Massas
5.
J Chromatogr A ; 1625: 461278, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709330

RESUMO

A fast, non-invasive, high-performance liquid chromatographic screening method with electrospray ionization mass spectrometric detection was developed for the analysis of three major glycine-conjugated bile acids in human saliva. Using a mobile phase composed of 80% methanol and 0.1% formic acid, glycocholic, glycodeoxycholic, and glycochenodeoxycholic acids were separated in less than 4 minutes with sensitivity in the low nM range. Bile acids are thought to contribute to the pathology of various complications in gastroesophageal reflux disease, for instance, Barrett's esophagus, which may eventually lead to esophageal carcinoma. In this pilot study, samples of saliva obtained from 15 patients with Barrett's esophagus of various severities were compared to saliva samples from 10 healthy volunteers. Glycochenodeoxycholic acid was significantly elevated in the patients and principal component analysis of all bile acids could distinguish the most severe Barrett's esophagus patients. We also reported on the detection of glycochenodeoxycholic acid in exhaled breath condensate for the first time. The promising results of this pilot study warrant future investigation, aiming at non-invasive diagnostics of Barrett's esophagus susceptibility in patients with gastroesophageal reflux disease.


Assuntos
Esôfago de Barrett/metabolismo , Ácidos e Sais Biliares/análise , Cromatografia Líquida de Alta Pressão/métodos , Saliva/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto , Esôfago de Barrett/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Análise de Componente Principal , Padrões de Referência , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador
6.
Acta Neuropathol Commun ; 8(1): 78, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493453

RESUMO

Treatment with small-molecule inhibitors, guided by precision medicine has improved patient outcomes in multiple cancer types. However, these compounds are often not effective against central nervous system (CNS) tumors. The failure of precision medicine approaches for CNS tumors is frequently attributed to the inability of these compounds to cross the blood-brain barrier (BBB), which impedes intratumoral target engagement. This is complicated by the fact that information on CNS penetration in CNS-tumor patients is still very limited. Herein, we evaluated cerebrospinal fluid (CSF) drug penetration, a well-established surrogate for CNS-penetration, in pediatric brain tumor patients. We analyzed 7 different oral anti-cancer drugs and their metabolites by high performance liquid chromatography mass spectrometry (HPLC-MS) in 42 CSF samples obtained via Ommaya reservoirs of 9 different patients. Moreover, we related the resulting data to commonly applied predictors of BBB-penetration including ABCB1 substrate-character, physicochemical properties and in silico algorithms. First, the measured CSF drug concentrations depicted good intra- and interpatient precision. Interestingly, ribociclib, vorinostat and imatinib showed high (> 10 nM), regorafenib and dasatinib moderate (1-10 nM) penetrance. In contrast, panobinostat und nintedanib were not detected. In addition, we identified active metabolites of imatinib and ribociclib. Comparison to well-established BBB-penetrance predictors confirmed low molecular weight, high proportion of free-drug and low ABCB1-mediated efflux as central factors. However, evaluation of diverse in silico algorithms showed poor correlation within our dataset. In summary, our study proves the feasibility of measuring CSF concentration via Ommaya reservoirs thus setting the ground for utilization of this method in future clinical trials. Moreover, we demonstrate CNS presence of certain small-molecule inhibitors and even active metabolites in CSF of CNS-tumor patients and provide a potential guidance for physicochemical and biological factors favoring CNS-penetration.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/líquido cefalorraquidiano , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Adolescente , Adulto , Antineoplásicos/farmacocinética , Transporte Biológico , Criança , Feminino , Humanos , Masculino , Adulto Jovem
7.
Cancers (Basel) ; 12(6)2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32466393

RESUMO

Molecular classification of medulloblastoma (MB) is well-established and reflects the cell origin and biological properties of tumor cells. However, limited data is available regarding the MB tumor microenvironment. Here, we present a mass spectrometry-based multi-omics pilot study of cerebrospinal fluid (CSF) from recurrent MB patients. A group of age-matched patients without a neoplastic disease was used as control cohort. Proteome profiling identified characteristic tumor markers, including FSTL5, ART3, and FMOD, and revealed a strong prevalence of anti-inflammatory and tumor-promoting proteins characteristic for alternatively polarized myeloid cells in MB samples. The up-regulation of ADAMTS1, GAP43 and GPR37 indicated hypoxic conditions in the CSF of MB patients. This notion was independently supported by metabolomics, demonstrating the up-regulation of tryptophan, methionine, serine and lysine, which have all been described to be induced upon hypoxia in CSF. While cyclooxygenase products were hardly detectable, the epoxygenase product and beta-oxidation promoting lipid hormone 12,13-DiHOME was found to be strongly up-regulated. Taken together, the data suggest a vicious cycle driven by autophagy, the formation of 12,13-DiHOME and increased beta-oxidation, thus promoting a metabolic shift supporting the formation of drug resistance and stem cell properties of MB cells. In conclusion, the different omics-techniques clearly synergized and mutually supported a novel model for a specific pathomechanism.

8.
Polymers (Basel) ; 11(7)2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288492

RESUMO

The influence of chlorinated water on the global and local aging behavior of polypropylene (PP) was investigated for three differently stabilized PP grades consisting of the same PP base polymer. While one of the PP grades contained only a processing stabilizer (PP-S0), the other two were modified with a primary phenolic antioxidant (PP-S1) and a combination of a primary phenolic antioxidant and a hindered amine stabilizer (PP-S3). To study global aging effects, micro-sized specimens were pre-exposed to chlorinated water (5 mg/L free chlorine) at 60 °C for up to 750 h. Over the entire exposure period, significant material aging was detected by monitoring a continuous decrease in stabilizer content, oxidation induction temperature, mean molar mass, and mechanical strain at break. In terms of aging resistance and ultimate mechanical performance, PP-S1 was found to outperform the other two material formulations under these test conditions. Moreover, superimposed mechanical-environmental fatigue tests with cracked round bar specimens were carried out with the three PP grades in non-chlorinated (0 mg/L free chlorine) and chlorinated (5 mg/L free chlorine) water at 80 °C and 95 °C to study local crack tip aging effects. While the fatigue crack growth resistance substantially deteriorated for all three materials in chlorinated water, a significantly stronger effect was found for the higher temperature, with crack growth rates at a given stress intensity factor range in chlorinated water being ca. 30 to 50 times faster than in non-chlorinated water, depending on the material. Molar mass measurements of material samples taken from various positions of the tested CRB specimens provided clear evidence of enhanced local crack tip aging due to the chlorinated water environment.

9.
Polymers (Basel) ; 11(6)2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167458

RESUMO

Polypropylene random copolymers (PP-R) are common materials for pressurized hot water pipes. In many pipe systems, potable water is disinfected by chlorine to prevent waterborne diseases. This paper deals with hot chlorinated water induced aging of two PP-R grades with varying morphology. One material had a conventional monoclinic α crystal form (PP-Rα), whereas the other was explicitly beta-nucleated resulting in a trigonal ß crystal form with a fine spherulite structure (PP-Rß). Micro-sized specimens with a thickness of 100 µm were used for aging experiments at 60 °C in chlorinated water with 5 mg/L free chlorine, and aging indicators were monitored for exposure times of up to 2000 h. On the other hand, superimposed mechanical-environmental tests were carried out by using cracked round bar specimens with a diameter of 14 mm to determine the fatigue crack growth (FCG) resistance of both PP-R grades at 60 °C in non-chlorinated and chlorinated water. PP-Rß was found to outperform PP-Rα with an about 30% higher time-to-embrittlement value of 2000 h. Furthermore, PP-Rß exhibited an enhanced FCG resistance in both non-chlorinated and chlorinated water. The effect of chlorine content on the deterioration of the FCG resistances was significantly more pronounced for PP-Rα.

10.
J Sep Sci ; 42(6): 1257-1264, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30637930

RESUMO

To date, the commonly used intravenous anesthetic propofol has been widely studied, and fundamental pharmacodynamic and pharmacokinetic characteristics of the drug are known. However, propofol has not yet been quantified in vivo in the target organ, the human brain. Here, cerebral microdialysis offers the unique opportunity to sample propofol in the living human organism. Therefore, a highly sensitive analytical method for propofol quantitation in small sample volumes of 30 µL, based on direct immersion solid-phase microextraction was developed. Preconcentration was followed by gas chromatographic separation and mass spectrometric detection of the compound. This optimized method provided a linear range between the lower limit of detection (50 ng/L) and 200 µg/L. Matrix-matched calibration was used to compensate recovery issues. A precision of 2.7% relative standard deviation between five consecutive measurements and an interday precision of 6.4% relative standard deviation could be achieved. Furthermore, the permeability of propofol through a cerebral microdialysate system was tested. In summary, the developed method to analyze cerebral microdialysate samples, allows the in vivo quantitation of propofol in the living human brain. Additionally the calculation of extracellular fluid levels is enabled since the recovery of the cerebral microdialysis regarding propofol was determined.


Assuntos
Líquido Cefalorraquidiano/química , Microdiálise , Propofol/análise , Microextração em Fase Sólida , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Humanos , Microdiálise/instrumentação , Microextração em Fase Sólida/instrumentação
11.
Eur J Radiol ; 101: 24-29, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29571797

RESUMO

OBJECTIVES: To compare the performance of screening with mammography combined with ultrasound versus mammography alone in women at average risk for breast cancer. METHODS: 66,680 women underwent physician-performed ultrasound as an adjunct to screening mammography. Histological results and follow-up at one year were used as reference standard for sensitivity. Main outcome measures were cancer detection rate, sensitivity, recall rate, biopsy rate, and positive predictive value of biopsy for combined screening with mammography plus ultrasound versus mammography alone. RESULTS: The overall sensitivity of mammography only was 61.5% in women with dense breasts and 86.6% in women with non-dense breasts. The sensitivity of mammography plus ultrasound combined was 81.3% in women with dense breasts and 95.0% in women with non-dense breasts. Adjunctive ultrasound increased the recall rate from 10.5 to 16.5 per 1000 women screened, and increased the biopsy rate from 6.3 to 9.3 per 1000 women screened. The positive predictive value of biopsy was 55.5% (95% CI 50.6%-60.3%) for mammography alone and 43.3 (95% CI 39.4%-47.3%) for combined mammography plus ultrasound. CONCLUSIONS: Supplemental ultrasound improves cancer detection in screening of women at average risk for breast cancer. Recall rates and biopsy rates can be kept within acceptable limits.


Assuntos
Neoplasias da Mama/prevenção & controle , Mamografia/métodos , Adulto , Idoso , Áustria/epidemiologia , Biópsia/estatística & dados numéricos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Fatores de Risco , Sensibilidade e Especificidade , Ultrassonografia Mamária/métodos
12.
J Vasc Interv Radiol ; 29(2): 262-267, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29273283

RESUMO

PURPOSE: To evaluate outcomes in patients with liver metastases from breast cancer treated with stereotactic radiofrequency (RF) ablation. MATERIALS AND METHODS: A retrospective analysis of 29 stereotactic RF ablation treatment sessions in 26 consecutive patients with 64 biopsy-proven breast cancer liver metastases (BCLMs) was conducted. Patients were included only if systemic treatment failed and all visible BCLMs were treatable. RESULTS: Primary and secondary technical success rates were 96.9% (62 of 64) and 100%, respectively. There were no perioperative mortalities. Local recurrence was identified in 5 tumors (7.8%), with no significant differences among tumor sizes (P = .662): < 3 cm (9.3%), 3-5 cm (0%), and > 5 cm (8.3%). Median estimated overall survival (OS) from first stereotactic ablation treatment was 29.3 months ± 8.9 (95% confidence interval [CI], 11.9-46.8 mo; mean, 28.7 mo) after a median follow-up of 23.1 months (mean, 31.3 mo; range, 0.1-100.8 mo). No significant differences in OS (P = .223) were observed among tumor volumes < 50 cm3 (median, 84.9 mo ± 53.1; mean, 58.4 mo), 50-100 cm3 (median, 37.8 mo ± 5.7; mean, 36.3 mo), and > 100 cm3 (median, 17.1 mo ± 3.5; mean, 21.8 mo). Numbers of metastases did not affect estimated OS, with a median OS of 32.7 months ± 10.4 (mean, 35.8 mo) for single lesions vs 17.7 months ± 3.2 (mean, 25.9 mo) for 2/3 lesions and a mean of 68.4 months ± 17.23 for > 3 lesions (P = .113). CONCLUSIONS: Multiple-electrode stereotactic RF ablation proved to be a safe minimally invasive alternative to surgical liver resection in selected patients with BCLMs.


Assuntos
Neoplasias da Mama/patologia , Ablação por Cateter/métodos , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Ondas de Rádio , Radiografia Intervencionista , Estudos Retrospectivos , Resultado do Tratamento , Carga Tumoral
13.
Wien Klin Wochenschr ; 130(3-4): 92-99, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29209825

RESUMO

BACKGROUND: Systems for the delivery of screening mammography vary among countries and these differences can influence screening effectiveness. We evaluated the performance of organized mammography screening for breast cancer combined with ultrasound in Tyrol / Austria, an approach that differs from many other population-based screening programs. METHODS: Data on women aged 40-69 years screened in the period from June 2008 to May 2012 were collected within the framework of an organized screening program. A total of 272,555 invitations were sent to the target population living in Tyrol and 176,957 screening examinations were performed. We analyzed the main performance indicators as defined by European Union (EU) guidelines and some important estimates of harms. RESULTS: The estimated 2­year participation rate was 56.9%. As ultrasound is implemented as second-line screening procedure, 76.2% of all women screened underwent supplementary ultrasound. In total 2322 women were recalled for further assessment (13.1 per 1000 screens) and 1351 biopsies were performed (7.6 per 1000 screens). The positive predictive value was 28.2% for assessment and 48.5% for biopsies. The cancer detection rate was 3.7 per 1000 screens and the proportion of all stage II+ screen-detected cancers was 35.5%. The interval cancer rate was 0.33 and 0.47 per 1000 screens in the first and second years, respectively. The estimated cumulative risk for a false positive screening result and an unnecessary biopsy for women following the invitation approach was 21.1% and 9.4%, respectively. CONCLUSION: The performance of our population-based screening approach combining mammography and ultrasound is very favorable and potential harm is kept very low compared to other European mammography screening programs for breast cancer.


Assuntos
Neoplasias da Mama , Mamografia , Adulto , Idoso , Áustria , Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer , Feminino , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Projetos Piloto
14.
J Sep Sci ; 39(6): 1056-66, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26778637

RESUMO

Hindered amine light stabilizers are an important class of stabilizers that protect synthetic polymers from degradation and thus from changing mechanical and optical properties. The current study presents an HPLC method capable of separating oligomeric hindered amine light stabilizers on a commercially available stationary phase, employing an MS-compatible novel mobile phase. Based on the exact masses observed with Q-TOF-MS, a comprehensive characterization of five different types of oligomeric hindered amine light stabilizers was achieved, leading to structural information not included in the datasheets provided by the suppliers. For the different investigated hindered amine light stabilizers, a number of recurring units up to 17 and a molecular weight of 5200 g/mol were detected. Furthermore, the analysis of stabilizer extracts of processed polypropylene samples containing different types of hindered amine light stabilizers revealed significant differences in the oligomeric pattern between standards and polymer samples. Thus, changes in the analytes' oligomeric pattern resulting from processing or aging of polymer materials can be monitored with the presented method.

15.
Electrophoresis ; 36(2): 348-54, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25308871

RESUMO

The combination of CE and MS is now a widely used tool that can provide a combination of high resolution separations with detailed structural information. Recently, we highlighted the benefits of an approach to add further functionality to this well-established hyphenated technique, namely the possibility to perform chemical reactions within the sheath-liquid of the CE-MS interface . Apart from using hydrogen/deuterium exchange for online determination of numbers of exchangeable protons, the addition of DPPH• (2,2-diphenyl-1-picrylhydrazyl) to the sheath-liquid can be used as a fast screening tool for studying antioxidant characteristics of individual components. Such a CE-MS methodology allows rapid and information-rich analysis with minimal reagent and sample consumption to be performed. In the present work, we demonstrate the applicability of this approach for the characterization of phenolic plant extracts from the Labiatae family, namely Rosmarinus officinalis and Melissa officinalis. Using the described approach, a wide range of compounds (15 and 13 phenolic compounds, respectively) could be confidently identified using a combination of high resolution CE-MS separations with implementation of online deuterium exchange and DPPH• reactions. These compounds included polyphenols, phenolic acids, and triterpene acids. In conjunction with online MS/MS experiments, extensive structural information for aglyconic and glycosylated antioxidants present in the extracts could be obtained using simple experimental changes, which can be carried out prior to the purchasing of expensive chemical standards or the time-consuming preparative isolation of individual compounds.


Assuntos
Eletroforese Capilar/métodos , Fenóis/análise , Extratos Vegetais/análise , Espectrometria de Massas em Tandem/métodos , Antioxidantes/análise , Compostos de Bifenilo/química , Medição da Troca de Deutério , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Melissa/química , Picratos/química , Extratos Vegetais/química , Rosmarinus/química , Espectrofotometria Ultravioleta
16.
J Sep Sci ; 37(22): 3195-204, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25146711

RESUMO

An anion-exchange liquid chromatography method for the determination of heparin and its impurities (dermatan sulfate and oversulfated chondroitin sulfate) was developed using chemometric-assisted optimization, including multivariate experimental design and response surface methodology. The separation of heparin, dermatan sulfate, and oversulfated chondroitin sulfate (Rs above 2.0) was achieved on a Dionex RF IC IonPac AS22 column with a gradient elution of 10-70% of 2.5 M sodium chloride and 20 mM Tris phosphate buffer (pH 2.1) at a flow rate of 0.6 mL/min and UV detection at 215 nm. Method validation shows good linearity (r > 0.99), acceptable precision (%relative standard deviations <11.4%) and trueness (%recovery of 92.3-103.9%) for all analytes. The limits of detection for dermatan sulfate and oversulfated chondroitin sulfate are equivalent to 0.11% w/w (10.5 µg/mL) and 0.07% w/w (7.2 µg/mL), while the limits of quantification are 0.32% w/w (31.5 µg/mL) and 0.22% w/w (22.0 µg/mL) relative to heparin, respectively. The method is specific for heparin, dermatan sulfate, and oversulfated chondroitin sulfate without interference from mobile phase and sample matrices and could be used for accurate quantitation the drug and its impurities in a single run. Applications of the method reveal contents of heparin between 90.3 and 97.8%. Dermatan sulfate and oversulfated chondroitin sulfate were not detected in any of the real-life samples.


Assuntos
Química Farmacêutica/métodos , Sulfatos de Condroitina/química , Cromatografia por Troca Iônica/métodos , Dermatan Sulfato/química , Contaminação de Medicamentos , Heparina/química , Animais , Anticoagulantes/química , Cromatografia Líquida de Alta Pressão , Mucosa Intestinal/metabolismo , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos , Raios Ultravioleta
17.
Anal Bioanal Chem ; 405(10): 3177-84, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23354576

RESUMO

A method for quantitative depth profiling of polymer stabilisers in polypropylene materials is presented. Microtome cuts down to 10 µm thickness were prepared and an amount of as low as 10 mg was used for subsequent analysis. The sample preparation procedure included dissolution in toluene, followed by precipitation of the polymer by addition of methanol or acetonitrile, and subsequent analysis of the solution by reversed phase HPLC coupled with UV, MS and MS(2) detection. A comparison of the different detection techniques is given and their particular advantages are discussed. Depending on the stabiliser type, the presented method with MS detection can quantify stabiliser concentrations down to 0.007 mg L(-1) (this corresponds to 0.0007 mg g(-1) in the polymer sample) with repeatabilities better than 5 % relative standard deviation (n = 3). This equals a quantitation of absolute stabiliser amounts at the 0.1-µg level and concentrations down to 0.1 mg L(-1) in the corresponding polymer extracts. The developed method shows high sensitivity by the use of MS detection as well as good repeatabilities. Mainly due to the use of an appropriate internal standard, improved repeatability during sample extraction could be obtained. Furthermore, the applicability to real samples has been demonstrated.

18.
BMC Public Health ; 11: 673, 2011 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-21878122

RESUMO

BACKGROUND: In Tyrol, Austria, the existing system of spontaneous mammography screening was switched in 2007 to an organised program by smoothly changing the established framework. This process followed most EU recommendations for organised mammography screening with the following exceptions: women aged 40-49 are part of the target population, screening is offered annually to the age group 40-59, breast ultrasound is available as an additional diagnostic tool, and double reading has not yet been implemented. After a pilot phase the program was rolled out to all of Tyrol in June 2008. The aim of this study was to analyse the performance of the organised screening system by comparing quality indices and recommended levels given in the well-established EU guidelines. METHODS: Working from the results of the pilot phase, we extended the organised mammography system to all counties in Tyrol. All women living in Tyrol and covered by compulsory social insurance were invited for a mammography, in the age group 40-59 annually and in the age group 60-69 biennially. Screening mammography was offered mainly by radiologists in private practice, with further assessment performed at hospitals. Using the screening database, all well-established performance indicators were analysed and compared with accepted/desired levels as per the EU guidelines. RESULTS: From June 2008 to May 2009, 120,440 women were invited. Per 1000 mammograms, 14 women were recalled for further assessment, nine underwent biopsy and four cancer cases were detected. Of invasive breast cancer cases, 32.3% and 68.4% were ≤ 10 mm and ≤ 15 mm in size, respectively, and 79.2% were node-negative. The positive predictive value for further assessment and for biopsy was 25.9% and 39.9%, respectively. Estimated two-year participation rate was 57.0%. In total, 14 interval cancer cases were detected during one year of follow-up; this is 18.4% of the background incidence rate. CONCLUSIONS: In Tyrol, Austria, an organised mammography screening program was implemented in a smooth transition from an existing spontaneous screening system and was completely rolled out within a short time. The high level of performance already seen in the pilot phase was maintained after rollout, and improvements resulting from the pilot phase were affirmed after one year of complete rollout.


Assuntos
Neoplasias da Mama/diagnóstico , Mamografia/métodos , Programas de Rastreamento/métodos , Avaliação de Programas e Projetos de Saúde , Adulto , Idoso , Áustria , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Garantia da Qualidade dos Cuidados de Saúde
19.
J Pharm Biomed Anal ; 56(1): 64-9, 2011 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-21620603

RESUMO

Development of a novel highly sensitive headspace sorptive extraction (HSSE) method in combination with thermal desorption gas chromatography coupled to a mass spectrometer (TD-GC/MS) allowed the identification of thymol and several phase I metabolites in human urine. Combined with an enzymatic hydrolysis of glucuronated or sulphated phase II metabolites of thymol and of the respective phase I metabolites prior to analysis, even trace quantities of hitherto not detected thymol phase I metabolites could be identified in urine samples of test persons after oral administration of 50mg thymol. It was proven, that human metabolism leads to a hydroxylation of the aromatic ring as well as of the iso-propyl side chain. Hydroxylation of the iso-propyl group results in the formation of the rather unstable p-cymene-3,8-diol and the corresponding dehydration product p-cymene-3-ol-8-ene which could be clearly detected in human urine samples. Furthermore, the aromatic hydroxylation products p-cymene-2,5-diol, its oxidation product p-cymene-2,5-dione and p-cymene-2,3-diol were also unambiguously identified by comparison with synthesized reference compounds.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Timol/metabolismo , Timol/urina , Adulto , Fracionamento Químico/métodos , Feminino , Temperatura Alta , Humanos , Masculino , Desintoxicação Metabólica Fase I
20.
BMC Public Health ; 11: 91, 2011 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-21306614

RESUMO

BACKGROUND: Efficiency and efficacy of organised mammography screening programs have been proven in large randomised trials. But every local implementation of mammography screening has to check whether the well established quality standards are met. Therefore it was the aim of this study to analyse the most common quality indices after introducing organised mammography screening in Tyrol, Austria, in a smooth transition from the existing system of opportunistic screening. METHODS: In June 2007, the system of opportunistic mammography screening in Tyrol was changed to an organised system by introducing a personal invitation system, a training program, a quality assurance program and by setting up a screening database. All procedures are noted in a written protocol. Most EU recommendations for organised mammography screening were followed, except double reading. All women living in Tyrol and covered by social insurance are now invited for a mammography, in age group 40-59 annually and in age group 60-69 biannually. Screening mammography is offered mainly by radiologists in private practice. We report on the results of the first year of piloting organised mammography screening in two counties in Tyrol. RESULTS: 56,432 women were invited. Estimated participation rate was 34.5% at one year of follow-up (and 55.5% at the second year of follow-up); 3.4% of screened women were recalled for further assessment or intermediate screening within six months. Per 1000 mammograms nine biopsies were performed and four breast cancer cases detected (N = 68). Of invasive breast cancer cases 34.4% were ≤ 10 mm in size and 65.6% were node-negative. In total, six interval cancer cases were detected during one year of follow-up; this is 19% of the background incidence rate. CONCLUSIONS: In the Tyrolean breast cancer screening program, a smooth transition from a spontaneous to an organised mammography screening system was achieved in a short time and with minimal additional resources. One year after introduction of the screening program, most of the quality indicators recommended by the European guidelines had been reached.However, it will be necessary to introduce double reading, to change the rule for BI-RADS 3, and to concentrate on actions toward improving the participation rate.


Assuntos
Neoplasias da Mama/diagnóstico , Mamografia/métodos , Programas de Rastreamento/organização & administração , Adulto , Idoso , Áustria , Neoplasias da Mama/epidemiologia , Feminino , Humanos , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Projetos Piloto
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