Test sensitivity of a commercial serine protease digestion kit for the detection of Trichinella spiralis and Trichinella pseudospiralis larvae in pig muscle.

The reference method for Trichinella detection at meat inspection is the magnetic stirrer method (MSM) utilising HCl-pepsin for pooled sample digestion. Due to availability and quality issues with pepsin, alternative digestion methods are being offered, such as the Priocheck Trichinella AAD kit (T-AAD), based on serine endopeptidase digestion. In this study the T-AAD kit was compared to the reference method. Minced pork samples were spiked with T. spiralis muscle larvae (ML) with- and without capsule or T. pseudospiralis ML, and analysed with both tests. Test results of individually spiked test samples were analysed by generalised linear modelling. The T-AAD test kit was comparable to the reference method for the qualitative detection of T. spiralis in pigs, but not quantitatively. Overall, 94% of spiked T. spiralis were recovered using MSM against 75.2% when using T-AAD (p < 0.0001). Using the MSM 80.0% of spiked T. pseudospiralis were recovered against 20% with the T-AAD (p < 0.0001). Based on our experience with the T-AAD kit, we strongly recommend validating the method on site prior to introduction into routine diagnostic laboratories, but this will not alleviate the poor test sensitivity of the T-AAD for the detection of T. pseudospiralis.

The effect of safinamide, a novel drug for Parkinson's disease, on pressor response to oral tyramine: a randomized, double-blind, clinical trial.

This randomized, double-blind, placebo-, comparator (selegiline 10 mg/day)-, and positive (phenelzine 30 mg/day)-controlled study investigated the pressor response to oral tyramine under fasting conditions after the administration of safinamide at therapeutic (100 mg/day) and supratherapeutic (350 mg/day) dosing regimens in healthy volunteers for the purpose of assessing the need for dietary restrictions. Pressor response was characterized by Tyr30, defined as the tyramine dose that triggers a sustained increase in systolic blood pressure (SBP) of ≥30 mm Hg as compared with baseline SBP. The primary end point was the tyramine sensitivity factor (TSF), defined as the ratio of Tyr30 at screening to Tyr30 under treatment. Safinamide induced a mild increase in TSF; however, the effect at each of the doses was numerically lower than those of the comparators (geometric mean TSFs: placebo, 1.52; safinamide 100 mg, 2.15; safinamide 350 mg, 2.74; selegiline, 3.12; phenelzine, 9.98). This study confirms that safinamide is a highly selective monoamine oxidase-B inhibitor, even at supratherapeutic doses, and suggests that it can be administered without tyramine-related dietary restrictions.

Possible role of MDR1 two-locus genotypes for young-age onset ulcerative colitis but not Crohn's disease.

BACKGROUND: The role of the single nucleotide polymorphisms (SNPs) on positions 2677G>T/A and 3435C>T of the multi-drug-resistance gene 1 (MDR1) in inflammatory bowel disease (IBD) remains unclear. AIMS: To further elucidate the potential impact of MDR1 two-locus genotypes on susceptibility to IBD and disease behaviour. PATIENTS AND METHODS: Three hundred eighty-eight German IBD patients [244 with Crohn's disease (CD), 144 with ulcerative colitis (UC)] and 1,005 German healthy controls were genotyped for the two MDR1 SNPs on positions 2677G>T/A and 3435C>T. Genotype-phenotype analysis was performed with respect to disease susceptibility stratified by age at diagnosis as well as disease localisation and behaviour. RESULTS: Genotype distribution did not differ between all UC or CD patients and controls. Between UC and CD patients, however, we observed a trend of different distribution of the combined genotypes derived from SNPs 2677 and 3435 (chi(2) = 15.997, df = 8, p = 0.054). In subgroup analysis, genotype frequencies between UC patients with early onset of disease and controls showed significant difference for combined positions 2677 and 3435 (chi(2) = 16.054, df = 8, p = 0.034 for age at diagnosis >or=25, lower quartile). Herein the rare genotype 2677GG/3435TT was more frequently observed (odds ratio = 7.0, 95% confidence interval 2.5 - 19.7). In this group severe course of disease behaviour depended on the combined MDR1 SNPs (chi(2) = 16.101, df = 6, p = 0.017 for age at diagnosis >or=25). No association of MDR1 genotypes with disease subgroups in CD was observed. CONCLUSIONS: While overall genotype distribution did not differ, combined MDR1 genotypes derived from positions 2677 and 3435 are possibly associated with young age onset of UC and severe course of disease in this patient group.

Volatile emissions from Aesculus hippocastanum induced by mining of larval stages of Cameraria ohridella influence oviposition by conspecific females.

Larval stages of the horse chestnut leafminer Cameraria ohridella can completely destroy the surface of horse chestnut leaves, Aesculus hippocastanum. This study investigated the effect of the degree of leaf browning caused by the insect's larvae on olfactory detection, aggregation, and oviposition of C. ohridella adults. The influence of A. hippocastanum flower scent on oviposition of the first generation was also evaluated. Utilizing gas chromatography coupled with parallel detection by mass spectrometry and electroantennography (GC-MS/EAD), more than 30 compounds eliciting responses from antennae of C. ohridella were detected. Oviposition and mining by C. ohridella caused significant changes in the profile of leaf volatiles of A. hippocastanum. After oviposition and subsequent mining by early larval stages (L1-L3), substances such as benzaldehyde, 1,8-cineole, benzyl alcohol, 2-phenylethanol, methyl salicylate, (E)-beta-caryophyllene, and (E,E)-alpha-farnesene were emitted in addition to the compounds emitted by uninfested leaves. Insects were able to detect these compounds. The emitted amount of these substances increased with progressive larval development. During late larval stages (L4, L5) and severe loss of green leaf area, (E,E)-2,4-hexadienal, (E/Z)-linalool oxide (furanoid), nonanal, and decanal were also released by leaves. These alterations of the profile of volatiles caused modifications in aggregation of C. ohridella on leaves. In choice tests, leaves in early infestation stages showed no significant effect on aggregation, whereas insects avoided leaves in late infestation stages. Further choice tests with leaves treated with single compounds led to the identification of substances mediating an increase or decrease in oviposition.

Elevated transaminases during medical treatment of acromegaly: a review of the German pegvisomant surveillance experience and a report of a patient with histologically proven chronic mild active hepatitis.

OBJECTIVE: The new GH receptor antagonist pegvisomant is the most effective medical therapy to normalize IGF-I levels in patients with acromegaly. Based on currently available data pegvisomant is well tolerated; however, treatment-induced elevation of transaminases has been reported and led to the necessity for drug discontinuation in some patients in the pivotal studies. The aim of this study was to evaluate and characterize the prevalence of elevated transaminases and to describe in detail the findings in a single case who required drug discontinuation because of elevation of transaminases which emerged during treatment and who underwent liver biopsy. DESIGN AND METHODS: Retrospective safety analyses were carried out on 142 patients with acromegaly receiving pegvisomant treatment in Germany between March 2003 and the end of 2004. Of these patients, 123 were documented in a post-marketing surveillance study, one case of elevated transaminases was reported spontaneously and the other patients were treated in a clinical study. RESULTS: Mean treatment duration with pegvisomant in the ongoing observational study at the end of 2004 was 28.3 +/- 19.9 (S.D.) weeks. Twelve out of the 142 patients had elevated transaminases above three times the upper limit of normal, likely caused by biliary obstruction in five of the patients. All patients but one affected by elevated transaminases had been previously treated with somatostatin analogues. In six out of 142 (4%) of patients, pegvisomant was permanently withdrawn because of elevated transaminases. The same number of patients showed a transient increase of transaminases with either spontaneous remission without dose modification (n = 4) or no re-increase of transaminases after temporary discontinuation and re-exposure (n = 2). The liver biopsy of one patient who was permanently withdrawn showed a chronic mild hepatitis with a mixed portal inflammation including eosinophilic granulocytes. CONCLUSIONS: Liver function tests should be regularly followed on pegvisomant treatment. Biliary complications, which may arise from restitution of normal gall bladder motility after cessation of somatostatin analogue treatment, need to be differentiated from pegvisomant-induced abnormalities. The histological pattern of the liver biopsy performed in one of the patients showed a mild chronic active hepatitis. The lack of dose dependency and rather low frequency of elevated transaminases in those cases where a biliary disorder was excluded render this reaction an idiosyncratic drug toxicity.

[Clinical drug investigations. Definition of terms]. / Arzneimitteluntersuchungen beim Menschen. Begriffserklärungen.

Implementation of the European Directive 2001/20/EC led to the inclusion of definitions for clinical trial and non-interventional trial in German Drug Law. Other terms, such as non-commercial clinical trial, single patient use, post marketing surveillance and public health study are less well defined. This article explains the various terms by comparing their differences and similarities.

Frequency of single nucleotide polymorphisms in the P-glycoprotein drug transporter MDR1 gene in white subjects.

BACKGROUND: P-glycoprotein, the gene product of MDR1, confers multidrug resistance against antineoplastic agents but also plays an important role in the bioavailability of common drugs in medical treatment. Various polymorphisms in the MDR1 gene were recently identified. A silent mutation in exon 26 (C3435T) was correlated with intestinal P-glycoprotein expression and oral bioavailability of digoxin. OBJECTIVE: We wanted to establish easy-to-use and cost-effective genotyping assays for the major known MDR1 single nucleotide polymorphisms and study the allelic frequency distribution of the single nucleotide polymorphisms in a large sample of volunteers. METHODS: In this study, the distribution of the major MDR1 alleles was determined in 461 white volunteers with the use of polymerase chain reaction and restriction fragment length polymorphism. RESULTS: Five amino acid exchanges were found with allelic frequencies of 11.2% for Asn21Asp and 5.5% for Ser400Asn. Strikingly, in exon 21 three variants were discovered at the same locus: 2677G (56.4%), 2677T (41.6%), and 2677A (1.9%), coding for 893Ala, Ser, or Thr. A novel missense Gln1107Pro mutation was found in two cases (0.2%). The highest frequencies were observed for intronic and silent polymorphisms; C3435T occurred in 53.9% of the subjects heterozygously, and 28.6% of individuals were homozygous carriers of 3435T/T with functionally restrained P-glycoprotein. CONCLUSION: This study provides the first analysis of MDR1 variant genotype distribution in a large sample of white subjects. It gives a basis for large-scale clinical investigations on the functional role of MDR1 allelic variants for bioavailability of a substantial number of drugs.

Hazardous pharmacokinetic interaction of Saint John's wort (Hypericum perforatum) with the immunosuppressant cyclosporin.

Contrary to common belief, over-the-counter herbal remedies may cause clinically relevant drug interactions. With the enclosed report we would like to alert other physicians that herbal extracts of Saint John's wort (Hypericum perforatum) may cause a sudden remarkable decrease of cyclosporin trough concentrations. A kidney transplantation patient treated with 75 mg bid doses of cyclosporin for many years experienced a sudden drop in her cyclosporin trough concentrations. This change was in temporal relationship to hypericum extract comedication, and a re-challenge gave similar results. The mean dose-normalized cyclosporin concentration during this comedication (90% confidence interval) was 0.48 (0.43 to 0.54) ng/(ml x mg) and was constantly below the respective concentration without the herbal remedy (0.84 (0.79 to 0.89) ng/(ml x mg)). This difference in the pharmacokinetics of cyclosporin indicates a relevant influence of St John's wort extract. The potential clinical consequence of this pharmacokinetic herb-drug interaction is apparent, since low cyclosporin levels are associated with an increased risk of rejection after organ transplantation and are usually not suspected upon intake of plant products. In view of the permanently increasing use of St John's wort preparations for various indications and the clinical relevance of this interaction, our report may contribute to the ongoing debate on the prescription status and safety of hypericum extracts.

Functional polymorphisms of the human multidrug-resistance gene: multiple sequence variations and correlation of one allele with P-glycoprotein expression and activity in vivo.

To evaluate whether alterations in the multidrug-resistance (MDR)-1 gene correlate with intestinal MDR-1 expression and uptake of orally administered P-glycoprotein (PGP) substrates, we analyzed the MDR-1 sequence in 21 volunteers whose PGP expression and function in the duodenum had been determined by Western blots and quantitative immunohistology (n = 21) or by plasma concentrations after orally administered digoxin (n = 8 + 14). We observed a significant correlation of a polymorphism in exon 26 (C3435T) of MDR-1 with expression levels and function of MDR-1. Individuals homozygous for this polymorphism had significantly lower duodenal MDR-1 expression and the highest digoxin plasma levels. Homozygosity for this variant was observed in 24% of our sample population (n = 188). This polymorphism is expected to affect the absorption and tissue concentrations of numerous other substrates of MDR-1.

Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (Hypericum perforatum).

OBJECTIVE: Extracts of St John's wort (Hypericum perforatum) are widely used in the treatment of depression, often as an over-the-counter drug. In contrast to its frequent use, knowledge about the pharmacokinetics of ingredients and drug interactions of St John's wort is poor. We studied the interaction between hypericum extract LI160 and digoxin. METHODS: The pharmacokinetics of digoxin were investigated in a single-blind, placebo-controlled parallel study. After the achievement of steady state for digoxin on day 5, healthy volunteers received digoxin (0.25 mg/d) either with placebo (n = 12) or with 900 mg/d LI160 (n = 13) for another 10 days. Digoxin concentration profiles on day 5 were compared with day 6 (single-dose interaction) and day 15 (tenth day of co-medication). RESULTS: There was a highly significant combined-day-and-group effect for digoxin area under the plasma concentration-time curve [AUC(0-24); P = .0001], peak concentration in plasma (Cmax; P = .0001), and plasma drug concentration at the end of a dosing interval (P = .0003) by two-way ANOVA. No statistically significant change was observed after the first dose of hypericum extract [AUC(0-24) at day 6 of 18.1+/-2.9 microg x h/L and 17.7+/-3.0 microg x h/L, mean +/- SD for placebo and hypericum group, respectively]. However, 10 days of treatment with hypericum extract resulted in a decrease of digoxin AUC(0-24) by 25% (day 15, 17.2+/-4.0 microg x h/L and 12.9+/-2.3 microg x h/L; P = .0035). Furthermore, comparison with the parallel placebo group after multiple dosing showed a reduction in trough concentrations and Cmax of 33% (P = .0023) and 26% (P = .0095), respectively. The effect became increasingly pronounced until the tenth day of co-medication. CONCLUSION: As with grapefruit juice, a food product, physicians should also be aware of potential drug-herb interactions. The interaction of St John's wort extract with digoxin kinetics was time dependent. The mechanism involved may be induction of the P-glycoprotein drug transporter.

Increase in cerivastatin systemic exposure after single and multiple dosing in cyclosporine-treated kidney transplant recipients.

OBJECTIVE: The mutual drug-drug interaction potential of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor cerivastatin and cyclosporine (INN, ciclosporin) in kidney transplant recipients receiving individual immunosuppressive treatment was evaluated with respect to pharmacokinetic behavior of either drug and tolerability of concomitant use. METHODS: Plasma and urine concentrations of cerivastatin and its major metabolites were determined after administration of 0.2 mg single-dose cerivastatin to 12 kidney transplant recipients (9 men and 3 women) who were receiving stable individual cyclosporine treatment (mainly 200 mg twice a day). These results were compared with the single-dose pharmacokinetic results obtained from a healthy control group (n = 12, age-comparable men). Cerivastatin steady-state pharmacokinetics were evaluated in the same patients during continued immunosuppressive treatment 4 to 6 weeks later, after a 7-day treatment of 0.2 mg cerivastatin once a day. Cyclosporine steady-state concentration-time profiles were determined in blood with monoclonal (EMIT [enzyme multiplied immunoassay technique] assay, parent drug specific) and polyclonal antibodies (FPIA [fluorescence polarization immunoassay] assay, cyclosporine plus metabolites) during cerivastatin cotreatment and compared with predosing data. RESULTS: Coadministration of 0.2 mg cerivastatin once a day to the kidney transplant recipients treated with individual doses of cyclosporine and other immunosuppressive agents resulted in a 3- to 5-fold increase in cerivastatin and metabolites plasma concentrations. Cerivastatin and metabolites elimination half-lives were unaffected, and no accumulation occurred during multiple-dosing conditions. Cerivastatin had no influence on steady-state blood concentrations of cyclosporine or cyclosporine metabolites in these patients. The concomitant use of both drugs was well tolerated. CONCLUSIONS: Cerivastatin and metabolites plasma concentrations were significantly increased in kidney transplant recipients treated with cyclosporine and other immunosuppressive agents. Displacement from the main site for cerivastatin distribution-the liver-by cyclosporine-inhibited liver transport processes may explain the decrease in both metabolic clearance and volume of distribution for cerivastatin and metabolites.