| 1. |
- Boström, Emma, et al.
(author)
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The Use of Liquid Chromatography/Mass Spectrometry for Quantitative Analysis of Oxycodone, Oxymorphone and Noroxycodone in Ringer Solution, Rat Plasma and Rat Brain Tissue
- 2004
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In: Rapid Communications in Mass Spectrometry. - : Wiley. - 0951-4198 .- 1097-0231. ; 18:21, s. 2565-2576
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Journal article (peer-reviewed)abstract
- Sensitive and reproducible methods for the determination of oxycodone, oxymorphone and noroxycodone in Ringer solution, rat plasma and rat brain tissue by liquid chromatography/mass spectrometry are described. Deuterated analogs of the substances were used as internal standards. Samples in Ringer solution were analyzed by direct injection of 10 microL Ringer solution diluted by an equal volume of water. The limit of quantification was 0.5 ng/mL and the method was linear in the range of 0.5-150 ng/mL for all substances. To analyze oxycodone and oxymorphone in rat plasma, 50 microL of plasma were precipitated with acetonitrile, and the supernatant was directly injected onto the column. To analyze oxycodone, oxymorphone and noroxycodone in rat plasma, 100 microL of rat plasma were subjected to a C18 solid-phase extraction (SPE) procedure, before reconstituting in mobile phase and injection onto the column. For both methods the limit of quantification in rat plasma was 0.5 ng/mL and the methods were linear in the range of 0.5-250 ng/mL for all substances. To analyze the content of oxycodone, oxymorphone and noroxycodone in rat brain tissue, 100 microL of the brain homogenate supernatant were subjected to a C18 SPE procedure. The limit of quantification of oxycodone was 20 ng/g brain, and for oxymorphone and noroxycodone 4 ng/g brain, and the method was linear in the range of 20-1000 ng/g brain for oxycodone and 4-1000 ng/g brain for oxymorphone and noroxycodone. All methods utilized a mobile phase of 5 mM ammonium acetate in 45% acetonitrile, and a SB-CN column was used for separation. The total run time of all methods was 9 min. The intra-day precision and accuracy were <11.3% and <+/-14.9%, respectively, and the inter-day precision and accuracy were <14.9% and <+/-6.5%, respectively, for all the concentrations and matrices described.
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| 2. |
- Jansson, Britt, et al.
(author)
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Simultaneous enantiospecific separation and quantitation of mephenytoin and its metabolites nirvanol and 4'-hydroxymephenytoin in human plasma by liquid chromatography.
- 2003
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In: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences. - 1570-0232 .- 1873-376X. ; 791:1-2, s. 179-91
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Journal article (peer-reviewed)abstract
- A high-performance liquid chromatographic method for the enantiospecific quantitation of S- and R-mephenytoin and its metabolites S- and R-nirvanol and S- and R-4'-hydroxymephenytoin in plasma is described. The compounds were separated using a reversed-phase C(2) column in tandem with a chiral alpha(1)-acid glycoprotein column and were detected using ultraviolet detection at 205 nm. The lower limit of quantification was 10 ng/ml for all compounds using 0.5 ml human plasma (intra-day coefficient of variation <13%, accuracy <+/-20%). The method was validated for human plasma in the concentration range 10-2000 ng/ml for each of the six compounds. The method allows for the simultaneous characterisation of the metabolic capacity of two human drug-metabolising enzymes, CYP2C19 and CYP2B6, and may be used when investigating polymorphisms or changes in activity of these two enzymes.
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| 3. |
- Jansson, Kjell, 1958-, et al.
(author)
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Intraperitoneal cytokine response after major surgery : higher postoperative intraperitoneal versus systemic cytokine levels suggest the gastrointestinal tract as the major source of the postoperative inflammatory reaction
- 2004
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In: American Journal of Surgery. - : Elsevier BV. - 0002-9610 .- 1879-1883. ; 187:3, s. 372-377
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Journal article (peer-reviewed)abstract
- BACKGROUND: Cytokine response is an important factor in the development of shock and organ failure. The aim of this study was to investigate intraperitoneal (peritoneal) and venous (systemic) postoperative cytokine release after major surgery.METHODS: Major abdominal surgery was performed in 19 patients. Preoperative systemic measurements and postoperative systemic and peritoneal measurements of C-reactive protein (CRP) and the cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin (IL-6), and IL-10 were performed.RESULTS: Significantly higher TNF-alpha, IL-6, and IL-10 peritoneal values were recorded compared with systemic values, whereas peritoneal CRP was significantly decreased. CRP increased significantly over time, whereas postoperative values of IL-6, IL-10, and peritoneal TNF-alpha decreased. Systemic TNF-alpha was constant over time, but values after emergent abdominal surgery showed a more extensive response. An additional effect of surgery and emergent abdominal disease was seen in increased TNF-alpha and IL-10 levels.CONCLUSIONS: Compared with systemic cytokines, peritoneal cytokines respond extensively after major surgery, indicating that measurement of peritoneal cytokines is a more sensible method to determine postoperative inflammatory reaction. A normal postoperative course is characterized by decreasing levels of peritoneal cytokines.
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| 4. |
- Jansson, Kjell, 1958-, et al.
(author)
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Results of intraperitoneal microdialysis depend on the location of the catheter
- 2004
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 64:1, s. 63-70
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Journal article (peer-reviewed)abstract
- Background and Objective: Intraperitoneal microdialysis was recently described as a method for early detection of visceral ischemia. The method seems safe and accurate. The intra-abdominal catheter used may imply variations in results depending on the location of the catheter. The aim of the study was to investigate possible differences in metabolic parameters obtained depending on various locations of the intra-abdominal catheter, compared with using the subcutaneous reference catheter. Method: After right-sided hemicolectomy in 12 patients, three catheters were placed and fixed intraperitoneally: one at the anastomosis, one in the omentum and one embedded between the small intestinal loops. A subcutaneous catheter placed in the pectoral region was used as reference. Analyses of lactate/pyruvate ratio and glucose and glycerol levels were done during a period of 45 hours postoperatively. Results: Lactate/pyruvate ratio decreased numerically at all three intraperitoneal locations during the study while the subcutaneous lactate/pyruvate ratio increased slightly. Significant differences between intraperitoneal and subcutaneous locations were found as well as differences between the three intraperitoneal locations. Highest values of the lactate/pyruvate ratio were found at the anastomosis, while the widest range was found at the small intestine. Subcutaneous glucose levels were lower while glycerol levels were higher compared with intraperitoneal values. Conclusions: In evaluating postoperative metabolism, intraperitoneal microdialysis is influenced by the location of the microdialysis catheter. The same pattern is, however, recorded over time. The juxta-anastomotic region and the small intestinal loop area seem to be the most reasonable locations for measurements.
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| 5. |
- Jansson, Ulla-Britt, 1950, et al.
(author)
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Voiding pattern in healthy children 0 to 3 years old: a longitudinal study.
- 2000
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In: The Journal of urology. - 0022-5347. ; 164:6, s. 2050-4
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Journal article (peer-reviewed)abstract
- PURPOSE: We describe the development of voiding patterns and bladder control in healthy children during the first 3 years of life. MATERIALS AND METHODS: We determined voiding patterns, bladder capacity and post-void residual urine volume per 4 hours individually and noninvasively every 3 months in 36 female and 23 male healthy infants using the 4-hour voiding observation. RESULTS: Voiding frequency decreased slowly from 5 to 2 voiding episodes per 4 hours from ages 3 months to 3 years. We noted interrupted voiding in 33% of subjects at age 3 months but this condition was rare after age 2 years. Voiding during sleep occurred mainly during the first 7 months of life and did not continue after age 18 months. Bladder capacity increased from a median of 52 to 67, 68 and 123 ml. during years 1 to 3, respectively. As measured by post-void residual urine volume, bladder emptying was unchanged during years 1 and 2 but it decreased during year 3 (median 6 versus 0 and mean 4 versus 3 ml. per 4 hours). CONCLUSIONS: During the first 3 years of life the number of voiding episodes, including interrupted voiding, post-void residual urine and voiding during sleep, decreased while bladder capacity increased.
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| 6. |
- Simonsson, Ulrika S H, et al.
(author)
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Artemisinin autoinduction is caused by involvement of cytochrome P450 2B6 but not 2C9.
- 2003
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In: Clinical pharmacology and therapeutics. - 0009-9236 .- 1532-6535. ; 74:1, s. 32-43
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Journal article (peer-reviewed)abstract
- Our goal was to investigate whether artemisinin autoinduction is caused by an increase in cytochrome P450 (CYP) 2B6 or CYP2C9 activities, we evaluated the effects of multiple-dose artemisinin administration on S-mephenytoin N-demethylation in healthy subjects.
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| 7. |
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