Influence of CYP2D6 and CYP2C19 genotypes on venlafaxine metabolic ratios and stereoselective metabolism in forensic autopsy cases.

We investigated whether polymorphisms in the CYP2D6 and CYP2C19 genes influence the metabolic ratios and enantiomeric S/R ratios of venlafaxine (VEN) and its metabolites O-desmethylvenlafaxine (ODV), N-desmethylvenlafaxine (NDV) and N,O-didesmethylvenlafaxine (DDV) in blood from forensic autopsy cases. In all, 94 postmortem cases found positive for VEN during toxicological screening were included. The CYP2D6 genotype was shown to significantly influence the ODV/VEN (P=0.003), DDV/NDV (P=0.010) and DDV/ODV (P=0.034) ratios. The DDV/ODV (P=0.013) and DDV/VEN (P=0.021) ratios were significantly influenced by the CYP2C19 genotype. The S/R ratios of VEN were significantly influenced by both CYP2D6 and CYP2C19 genotypes. CYP2D6 poor metabolizers (PMs) had lower S/R VEN ratios and CYP2C19 PMs had high S/R ratios of VEN in comparison. Our results show that the CYP2D6 genotype influences the O-demethylation whereas CYP2C19 influences the N-demethylation of VEN and its metabolites. In addition, we show a stereoselective metabolism where CYP2D6 favours the R-enantiomer whereas CYP2C19 favours the S-enantiomer.

Retention of opioids and their glucuronides on a combined zwitterion and hydrophilic interaction stationary phase.

A stationary phase combining zwitterionic ion chromatography and hydrophilic interaction chromatography (ZIC-HILIC) from SeQuant was evaluated for the chromatography of some opiates and their polar metabolites. The effects of mobile phase constitution on retention and resolution were extensively evaluated. Different aspects of mobile phase constitution such as ion strength and type of buffer, type and amount of organic modifier and pH were examined. The selectivity and retention of the opiates compared to their glucuronides could be substantially altered with small changes of the mobile phase, especially when the type of buffer, i.e., formate or acetate and organic modifier, i.e., acetonitrile or methanol were changed. The retention on the ZIC-HILIC was dominated by hydrophilic interaction chromatography (HILIC) but considerable effects on the selectivity was observed, possibly caused by an ion exchange mechanism due to interactions with the charges on the stationary phase.

Quantitation of seven low-dosage antipsychotic drugs in human postmortem blood using LC-MS-MS.

In forensic toxicology, antipsychotic drugs are of considerable interest because of their abuse potential and their involvement in intoxications and suicides. In recent years, several new drugs dosed at low levels have entered the market and have put further demands on assays used. The aim of this work was to develop a validated liquid chromatography-tandem mass spectrometry assay for the quantitation of the low-dosage antipsychotic drugs buspirone, fluphenazine, flupenthixol, perphenazine, risperidone, ziprasidone, and zuclopenthixol in human postmortem blood. After liquid-liquid extraction using methyl t-butyl ether, compounds were separated on a Zorbax SB-CN column. Calibration curves were linear in the range 0.8-100 microg/L (r > 0.998) for all drugs. Both within- and between-day coefficients of variation were lower than 25% for all drugs at the LOQ, and extraction recoveries ranged between 58 and 112%. The possible presence of matrix effects was closely investigated. Fifty-four authentic samples were analyzed within the routine postmortem investigation, which resulted in the diagnosis of three fatal intoxications. Even though only a few intoxications were identified, the assay may present valuable information on suicidal deaths in psychotic patients where a true negative result implies noncompliance and a higher susceptibility for suicide. Without a sensitive enough method, this conclusion cannot be drawn. Therefore, we believe that antipsychotic drugs must be measured not only in toxic concentrations but also in therapeutic levels in postmortem cases.

Quality Indicators of Nutritional Care Practice in Elderly Care.

OBJECTIVES: The aim is to explore the effects of antecedent, structural and process quality indicators of nutritional care practice on meal satisfaction and screened nutritional status among older adults in residential care homes. DESIGN: Data for this Swedish cross-sectional study regarding older adults living in residential care homes were collected by i) a national questionnaire, ii) records from the quality registry Senior Alert, iii) data from an Open Comparison survey of elderly care in 2013/2014. The data represented 1154 individuals in 117 of 290 Swedish municipalities. MEASUREMENTS: Meal satisfaction (%) and adequate nutritional status, screened by the Mini Nutritional Assessment Short Form (MNA-SF), were the two outcome variables assessed through their association with population density of municipalities and residents' age, together with 12 quality indicators pertaining to structure and process domains in the Donabedian model of care. RESULTS: Meal satisfaction was associated with rural and urban municipalities, with the structure quality indicators: local food policies, private meal providers, on-site cooking, availability of clinical/community dietitians, food service dietitians, and with the process quality indicators: meal choice, satisfaction surveys, and 'meal councils'. Adequate nutritional status was positively associated with availability of clinical/community dietitians, and energy and nutrient calculated menus, and negatively associated with chilled food production systems. CONCLUSION: Municipality characteristics and structure quality indicators had the strongest associations with meal satisfaction, and quality indicators with local characteristics emerge as important for meal satisfaction. Nutritional competence appears vital for residents to be well-nourished.

Evaluation of electrospray ionisation liquid chromatography-tandem mass spectrometry for rational determination of a number of neuroleptics and their major metabolites in human body fluids and tissues.

A study of liquid chromatography-triple quadrupole mass spectrometry (LC-MS-MS) with positive electrospray ionisation (ESI) for the determination of selected drugs in human tissues and body fluids such as blood, urine and hair is described. The possibility to screen for and quantify the 19 most commonly prescribed neuroleptics on the Swedish market and determine the presence of their major metabolites within a single LC-MS-MS analysis was evaluated on a PE Sciex API2000 instrument. Chromatographic conditions were optimised and the best separation, with individual retention times for most of the analytes, was obtained on a Zorbax SB-CN column within a 9-min gradient run. The MS-MS fragmentation conditions were optimised for each compound in order to obtain both specific fragments and high signal intensity. Since neuroleptics are a heterogeneous group of compounds, a markedly difference in collision energy needed to achieve fragments of the selected parent ions was seen and the number of fragments achieved varied as well. For sensitive quantification the transition of the most intense fragment of the protonated molecular ion (M+1)(+) was selected for multiple reaction monitoring analysis. More than 70 transitions were finally included in the assay. Detection levels down to the lower ng/ml level were achieved for all analytes, but between analytes more than a 10-fold difference in signal response was seen. By evaluation of extracted ion chromatograms from the analysis of authentic human blood, urine and hair sample the proposed concept for rational drug analysis was found to be both selective and sensitive for the neuroleptics included. A great number of metabolites could be determined in blood, urine and hair as well. A full method validation was not performed since the objective was to evaluate the method design rather than to validate a final method set-up.

Coupled-column chromatography on a Chiral-AGP phase for determination of amlodipine enantiomers in human plasma: an HPLC assay with electrochemical detection.

A sensitive enantioselective high performance liquid chromatographic assay for determination of the dihydropyridine-type calcium antagonist amlodipine in human plasma samples is described. Chiral chromatography is performed on an alpha 1-acid glycoprotein column (i.e. Chiral-AGP) and the eluted enantiomers are trapped and compressed on two short columns before final achiral chromatography on a narrow bore column (i.e. Zorbax SB-Ph) using electrochemical detection. Both stereoselective quantitative analysis and enantiomeric ratio analysis, for samples with a known total concentration of amlodipine are described. The quantitative assay shows linearity over the range 0.5-10 ng ml-1 for the two enantiomers and the limit of detection is about 0.2 ng ml-1. The method has been applied to a pharmacokinetic study of the enantiomers of amlodipine in human subjects.

The environmental consequences of alien species in the Swedish lakes Mälaren, Hjälmaren, Vänern and Vättern.

Twenty alien species have become established in the lakes Mälaren, Vänern, Vättern and Hjälmaren. Intentional introductions include fish and the signal crayfish from North America, ornamental plants, and the Canada goose. Unintentional introductions include the crayfish plague introduced with infected crayfish, the zebra mussel, and Chinese mitten crab introduced with ballast water. The introduction of pathogens and parasites, in particular the crayfish plague, to the lakes has had the greatest environmental and socioeconomic effects and has contributed to the decimation of the indigenous noble crayfish. The stocking of brown trout and salmon with origins from different biogeographical regions has contributed to the extinction of relict indigenous fish species in L. Vänern. Although major ecosystem damage caused by the introduction of alien species, with the exception of the crayfish plague, has not occurred in the four large Swedish lakes, local problems of considerable dignity occur occasionally.

Effects of metabolic inhibition on cytoplasmic calcium and contraction in smooth muscle of rat portal vein.

Contractions in the rat portal vein, evoked by spontaneous action potentials or depolarizing high-K+ solution, are rapidly and reversibly inhibited by hypoxia or respiratory blockade. Intracellular free calcium ([Ca2+]i) was measured using Fura-2 to evaluate the effects of metabolic blockade on excitation-contraction coupling. Spontaneous contractions were associated with transient increases in [Ca2+]i. During exposure to cyanide (0.2-0.4 mM) or 2,4-dinitrophenol (30 microM) the duration and amplitude of the Ca2+ transients were decreased, leading to a decreased mean time integral of the individual [Ca2+]i transient, and corresponding decrease in the duration and amplitude of the contraction. Basal [Ca2+]i was increased in the presence of the metabolic inhibitors. High-K+ (40 mM) contractions caused a sustained increase in [Ca2+]i, which was not inhibited by exposure to cyanide, although the amplitude of the associated contraction was greatly reduced. Together with the earlier demonstration of decreased 20 kD myosin light chain phosphorylation under these conditions, this indicates that the activation of contraction is influenced by metabolism via the energy dependence of the light chain phosphorylation reaction. Thus at least three steps in the excitation-contraction sequence are influenced by inhibition of oxidative metabolism: membrane excitation, light chain phosphorylation, and the cross-bridge cycle. This provides mechanisms for a high degree of metabolic sensitivity of vascular tone, of importance for the adaptation of blood flow to tissue metabolic demands.

Working capacity and quality of life after undergoing an ileostomy.

The purpose of this paper is to describe the life situation, the frequency of sick-listing and the work situation of people with ulcerative colitis and Crohn's disease who have undergone an ileostomy. The survey which was undertaken in Sweden included 53 people between the ages of 17 and 65 who had had their ileostomy for between 6 months and 25 years. Personal interviews were carried out and information about the operation and complications was acquired from the medical records. Half of the respondents felt themselves handicapped to some extent. Despite this, most of them did not consider their daily activities to be adversely affected by the sickness/ileostomy. There were, however, individual variations depending on the sickness, how well the ileostomy worked and other factors affecting the individual's situation. Twenty-two had been off sick once or several times during the previous 2 years; nine of them had been sick-listed over a longer period. Most of them stated that their working capacity had not been affected by the operation/sickness, while 10 of them had some form of disability pension or part-time work. A positive reaction noted was that when the sickness no longer steered one's life, it became easier to plan both work and leisure time.

Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers.

OBJECTIVE: This study was performed to assess whether coadministration with grapefruit juice significantly affects the pharmacokinetics of amlodipine, a dihydropyridine class calcium antagonist with slow absorption, distribution and low plasma clearance. The primary objective was to evaluate whether short exposure to grapefruit juice could affect the metabolism of amlodipine to an extent similar to that previously demonstrated for other dihydropyridines (e.g. felodipine, nisoldipine, nitrendipine). METHODS: Twelve healthy male volunteers followed a randomised, open crossover study design, comparing the effect of a single oral dose of amlodipine (5 mg) taken together with a glass of grapefruit juice (250 ml) vs water. Blood samples to determine plasma concentration were taken and blood pressure (BP) and heart rate (HR) were measured throughout the study. RESULTS: When amlodipine was coadministered with grapefruit juice, Cmax was 115% and AUC(0-72 h) was 116% compared with water, but tmax was not significantly changed. There were no significant differences in BP and HR between the two treatments. A small decrease in diastolic BP, however, was observed in both treatments 4-8 h after drug administration, coinciding with Cmax, but this was normalised after 12 h. The BP reduction seen was compensated by a slight increase in HR, which remained throughout the study. CONCLUSION: An interaction between grapefruit juice and amlodipine was demonstrated. The haemodynamic data showed that a dose of 5 mg was sufficient to achieve a BP reduction in healthy subjects, but the increase in amlodipine plasma concentration seen after intake of grapefruit juice was too small to significantly affect BP or HR. The clinical significance of this food/drug interaction, however, cannot be ignored since there is considerable variation between individuals and a more extensive intake of grapefruit juice might give more pronounced effects.

Inhibition of nisoldipine on bovine mesenteric arteries and veins and on human peripheral veins.

The inhibiting effect of the calcium channel blocker nisoldipine (CAS 63675-72-9, Baymycard, Syscor) on potassium-induced contraction on bovine mesenteric veins and arteries and human peripheral veins was investigated. Nisoldipine inhibited the contraction on bovine mesenteric veins at a significantly lower concentration (1 x 10(-10) mol/l) than nifedipine and glyceryl trinitrate (GTN) (1 x 10(-7) mol/l). When the preparations were preincubated with the drugs, nisoldipine reduced the contraction, measured as area under the curve (AUC), with 47 +/- 8% (mean +/- SEM) and nifedipine with 29 +/- 13% in veins. It was necessary to use an inconsiderably higher concentration of nisoldipine to relax bovine mesenteric arteries contracted by potassium. Preincubation of these arteries with nisoldipine (1 x 10(-7) mol/l) reduced contraction measured as AUC by 46 +/- 10% and preincubation with nifedipine (1 x 10(-7) mol/l) by 77 +/- 3%. Nisoldipine also caused a marked relaxation in human saphenous veins. The introduction of nisoldipine (1 x 10(-8) mol/l) after potassium-induced contraction caused 54 +/- 8% relaxation.

Sensitive high-performance liquid chromatographic analysis of amlodipine in human plasma with amperometric detection and a single-step solid-phase sample preparation.

A narrow-bore HPLC assay with electrochemical detection for the determination of the calcium antagonist amlodipine in human plasma samples is presented. By using a single-step solid-phase extraction procedure on Bond Elut C2 columns, the sample preparation step has been considerably simplified and less time-consuming compared to earlier presented works. With a linear and reproducible calibration curve over the range 0.5-20 ng ml-1 plasma, the assay has successfully been used in the analysis of more than 500 plasma samples from a multicenter trial.

Sodium/iodide-symporter: distribution in different mammals and role in entero-thyroid circulation of iodide.

UNLABELLED: The sodium (Na+)/iodide (I-)-symporter (NIS) is abundantly expressed and accumulates iodide in thyroid follicular cells. The NIS is also found in extrathyroidal tissues, particularly gastric mucosa. Controversies exist on the localization of extrathyroidal NIS. We have studied the presence of both NIS peptide and NIS messenger RNA (mRNA) in the digestive tract and thyroid from different mammals. The role of gastric NIS is enigmatic and we aimed to unravel its possible involvement in iodide transport. METHODS: Distribution and expression of NIS were studied using immunocytochemistry and in situ hybridization. Iodide transport in the gastrointestinal tract was measured after oral or intravenous (i.v.) administration of 125I to rats with or without ligation of the pylorus. RESULTS: All thyroid follicular cells in rat and mouse expressed NIS, whereas a patchy staining was noted in man, pig and guinea-pig. Gastric mucosa surface epithelium in all species and ductal cells of parotid gland in guinea-pig, rat and mouse expressed NIS. In parietal cells and in endocrine cells of intestines and pancreas NIS immunoreactivity but no NIS mRNA was found. Studies of 125I uptake showed marked iodide transport from the circulation into the gastric lumen. CONCLUSIONS: The localization of NIS varies slightly among mammals. To establish expression of NIS in a particular cell type the need to correlate the presence of both NIS protein by immunocytochemistry and NIS mRNA by in situ hybridization is emphasized. An entero-thyroidal circulation of iodide mediated principally by gastric NIS, but possibly also by NIS in salivary glands is suggested.

Carbonic anhydrase activity and sweat gland morphology in trained and untrained Standardbred trotters.

Sweat gland morphology and carbonic anhydrase (CA) distribution was studied after exercise in trained and untrained horses using a histochemical technique and light microscopic image analysis. Three trained and 3 untrained Standardbred trotters performed an exercise test (20 min trot at 6 m/s with 5 min walk at 1.8 m/s in the beginning and end) on a high-speed treadmill at 35 degrees C. Skin biopsies were taken before exercise and after trot. The fluid loss after exercise was 10, 12 and 12 g/kg bwt in the untrained horses and 4, 6 and 11 g/kg in the trained. Trained horses had a larger cell area than untrained after exercise, which might be related to an increase in secretory capacity. The area of the cell occupied by CA was independent of training status, but increased with exercise in both groups. The CA activity was higher in untrained animals and increased after exercise in both groups. The change in CA during exercise might be a response to an increasing demand for HCO3- secretion during sweat formation. Therefore, the sweat gland undergoes morphological changes due to stimuli such as heat, exercise and training, but species differences are evident. To our knowledge, no one has previously studied the influence of training on the morphology of the equine sweat gland.

Effect of recombinant neutral endopeptidase (EC 3.4.24.11) on neuropeptide-mediated nasal fluid secretion and plasma exudation in the rat.

The nasal mucosa harbors sensory nerves containing neuropeptides such as substance P (SP), which are released by capsaicin. The neuropeptides are degraded by peptidases, e.g., neutral endopeptidase (NEP) that is present in the nasal mucosa. We studied the effect of enzymatically active recombinant NEP (rNEP) on neuropeptide-evoked secretion of nasal fluid and plasma exudation in rats. rNEP administered intranasally (i.n.) reduced the capsaicin-evoked nasal fluid secretion but failed to reduce the secretion evoked by SP (exogenous) under the experimental conditions used. rNEP reduced the increase in nasal plasma exudation evoked by capsaicin (endogenous neuropeptides). Because rNEP reduced neuropeptide-mediated nasal fluid secretion and plasma exudation in the rat, we suggest that peptidase activity in the nasal mucosa will determine the magnitude of the response to locally released neuropeptides.