In depth behavioral phenotyping unravels complex motor disturbances in Cstb-/- mouse, a model for progressive myoclonus epilepsy type 1.

Progressive myoclonus epilepsy type 1 (EPM1) is an autosomal recessively inherited childhood-adolescence onset neurodegenerative disease caused by mutations in the cystatin B (CSTB gene). The key clinical manifestation in EPM1 is progressive, stimulus-sensitive, in particular action-induced myoclonus. The cystatin B-deficient mouse model, Cstb-/-, has been described to present with myoclonic seizures and progressive ataxia. Here we describe results from in-depth behavioral phenotyping of the Cstb-/- mouse model in pure isogenic 129S2/SvHsd background covering ages from 1.5 to 6 months. We developed a method for software-assisted detection of myoclonus from video recordings of the Cstb-/- mice. Additionally, we observed that the mice were hyperactive and showed reduced startle response, problems in motor coordination and lack of inhibition. We were, however, not able to demonstrate an ataxic phenotype in them. This detailed behavioral phenotyping of the Cstb-/- mice reveals new aspects of this mouse model. The nature of the motor problems in the Cstb-/- mice seems to be more complex and more resembling the human phenotype than initially described.

Genetic and serological typing of European infectious haematopoietic necrosis virus (IHNV) isolates.

Infectious haematopoietic necrosis virus (IHNV) causes the lethal disease infectious haematopoietic necrosis (IHN) in juvenile salmon and trout. The nucleocapsid (N) protein gene and partial glycoprotein (G) gene (nucleotides 457 to 1061) of the European isolates IT-217A, FR-32/87, DE-DF 13/98 11621, DE-DF 4/99-8/99, AU-9695338 and RU-FR1 were sequenced and compared with IHNV isolates from the North American genogroups U, M and L. In phylogenetic studies the N gene of the Italian, French, German and Austrian isolates clustered in the M genogroup, though in a different subgroup than the isolates from the USA. Analyses of the partial G gene of these European isolates clustered them in the M genogroup close to the root while the Russian isolate clustered in the U genogroup. The European isolates together with US-WRAC and US-Col-80 were also tested in an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies (MAbs) against the N protein. MAbs 136-1 and 136-3 reacted equally at all concentrations with the isolates tested, indicating that these antibodies identify a common epitope. MAb 34D3 separated the M and L genogroup isolates from the U genogroup isolate. MAb 1DW14D divided the European isolates into 2 groups. MAb 1DW14D reacted more strongly with DE-DF 13/98 11621 and RU-FR1 than with IT-217A, FR-32/87, DE-DF 4/99-8/99 and AU-9695338. In the phylogenetic studies, the Italian, French, German and Austrian isolates clustered in the M genogroup, whereas in the serological studies using MAbs, the European M genogroup isolates could not be placed in the same specific group. These results indicate that genotypic and serotypic classification do not correlate.

Effect of the novel anxiolytic drug deramciclane on cytochrome P(450) 2D6 activity as measured by desipramine pharmacokinetics.

BACKGROUND: In vitro findings have indicated that the novel anxiolytic drug, deramciclane, is an inhibitor of the cytochrome P(450) (CYP) 2D6 enzyme and co-administration of deramciclane and the CYP2D6 probe drug desipramine is possible in clinical practice. OBJECTIVE: To evaluate the effects of deramciclane on CYP2D6 activity as measured by desipramine pharmacokinetics and pharmacodynamics using paroxetine as a positive control for CYP2D6 inhibition. METHODS: Fifteen healthy subjects received either 60 mg deramciclane, 20 mg paroxetine or matched placebo for 8 days in randomized order in this double-blind, cross-over study. On day 8 of each study phase, the subjects received a 100-mg single dose of desipramine. Desipramine and its CYP2D6-dependent metabolite, 2-OH-desipramine, concentrations were measured for 240 h. Measurement of secretion of saliva, Visual Analogue Scale assessment of dryness of mouth and tiredness were carried out on day 7 and day 8 to assess the pharmacodynamic consequences of deramciclane or paroxetine co-administration with desipramine. RESULTS: Repeated administration of deramciclane doubled the AUC of desipramine ( P<0.001), while paroxetine caused a 4.8-fold increase in the AUC of desipramine ( P<0.001). Significant correlations were observed with paroxetine (r(s)=0.84, P<0.001) and deramciclane (r(s)=0.51, P=0.0498) concentrations and the magnitude of increase of desipramine AUC. Both deramciclane and paroxetine decreased the formation of 2-OH-desipramine in the first-pass phase. The AUC ratio of 2-OH-desipramine/desipramine was decreased by 39% ( P<0.001) by deramciclane and by 74% ( P<0.001) by paroxetine. There were no changes in the secretion of saliva during co-administration of desipramine with deramciclane compared with placebo. CONCLUSION: Although deramciclane seems to be a weaker inhibitor of CYP2D6 than paroxetine, dose adjustment of drugs metabolized by CYP2D6 may be needed when used concomitantly with deramciclane.

Pharmacokinetics of deramciclane, a novel anxiolytic agent, after intravenous and oral administration.

BACKGROUND AND OBJECTIVE: Deramciclane is a new compound that has shown anxiolytic effects in animal experiments and in human studies. The aim of this study was to determine the pharmacokinetic parameters of deramciclane after intravenous and oral administration, and its oral bioavailability. METHODS: Deramciclane 30 mg was given intravenously and orally as a tablet and as solution in an open, randomised, crossover three-period trial to 12 healthy male volunteers. Oral bioavailability of deramciclane and the pharmacokinetic parameters of deramciclane and N-desmethylderamciclane, the principal metabolite, were determined after intravenous and oral administration of the parent drug. RESULTS: The first and second distribution half-lives (mean +/- SD) of deramciclane were 0.04 +/- 0.01 and 3.03 +/- 0.50h, respectively, and the half-life of the elimination phase was 26.6 +/- 5.5h. The clearance of deramciclane after an intravenous dose was 0.24 +/- 0.10 L/kg. The elimination phase half-life of N-desmethylderamciclane was 38.2 +/- 6.9h after intravenous and about 25 h after oral dosing of the parent compound. The mean oral bioavailability of deramciclane was 44% (range 27-58%) and 36% (23-50%) after administration of the oral solution and tablet, respectively. Deramciclane was well tolerated even after a 30 mg intravenous dose resulting in peak plasma concentrations 10 times higher than observed after its oral administration. CONCLUSIONS: After intravenous administration, the pharmacokinetics of deramciclane are adequately described by a three-compartment model. After oral administration its pharmacokinetics follow a two-compartment model with first-order absorption. The elimination phase half-life of the parent compound is similar after intravenous and oral administration, whereas the apparent half-life of N-desmethylderamciclane is longer after intravenous than after oral administration of the parent compound. The oral bioavailability of deramciclane is large and uniform enough to allow its clinical use as tablets.

Effect of the novel anxiolytic drug deramciclane on the pharmacokinetics and pharmacodynamics of the CYP3A4 probe drug buspirone.

RATIONALE: Preliminary in vitro findings indicated that the novel anxiolytic drug, deramciclane is a substrate for the cytochrome P(450) (CYP) 3A4 isoenzyme. Moreover, its co-administration with buspirone, another anxiolytic drug, is likely in clinical practice. OBJECTIVES: The primary objective of the present study was to evaluate the in vivo effects of deramciclane on CYP3A4 activity as measured by buspirone pharmacokinetics. The secondary objective was to study the possible pharmacodynamic interaction between these two anxiolytic drugs. METHODS: Sixteen healthy subjects received 60 mg deramciclane or matched placebo for 8 days in this randomized, double-blind, cross-over study. On day 8 of both phases, the subjects received a 20-mg single dose of buspirone. Buspirone and its active metabolite, 1-pyrimidylpiperazine (1-PP), concentrations were measured for 24 h. Pharmacodynamic testing and measurement of plasma prolactin concentrations were carried out on day 7 and day 8 to assess the pharmacodynamic consequences of deramciclane and buspirone co-administration. RESULTS: Repeated administration of deramciclane had no effect on CYP3A4 activity as measured by buspirone pharmacokinetics. However, deramciclane administration caused an inhibition of the further, not CYP3A4-dependent, metabolism of 1-PP as evidenced by 84% increase in the AUC ( P<0.001) and 20% increase in the elimination half-life ( P=0.0012) of 1-PP. Deramciclane did not potentiate the buspirone-induced increase in prolactin secretion. No significant differences were found in the psychomotoric testing or the subjective maximum sedation between the deramciclane phase and the placebo phase, either before or after buspirone administration. Of 16 subjects, 5 experienced dizziness during both study phases. CONCLUSION: Deramciclane does not inhibit CYP3A4 activity as measured by buspirone pharmacokinetics, and there were no indications of relevant pharmacodynamic interaction after multiple doses of deramciclane and a single dose of buspirone.

A novel fish rhabdovirus from sweden is closely related to the Finnish rhabdovirus 903/87.

A novel rhabdovirus, preliminary designated as the Sea trout rhabdovirus 28/97 (STRV 28/97), was isolated from sea trout (Salmo trutta trutta) in Sweden in 1996. The fish showed central nervous symptoms, and at the autopsy petechial bleedings in the mesenteric fat were visible. STRV 28/97 was shown to be serologically related to the vesiculotype rhabdovirus 903/87 isolated from brown trout (Salmo trutta lacustris) in Finland [1,3]. The sequences for the nucleocapsid protein, phosphoprotein, matrix protein, glycoprotein and beginning of the polymerase protein of STRV 28/97 were determined. At the amino acid level the genes were over 97% similar to virus 903/87. The nucleocapsid proteins, glycoproteins and beginning of the polymerase protein of STRV 28/97 and virus 903/87 were clustered with the vesiculoviruses and the phosphoproteins close to the vesiculoviruses in protein parsimony analysis. The matrix proteins formed a distinct clade in protein parsimony analysis.

Immunolocalization of cysteine proteinases (cathepsins) and cysteine proteinase inhibitors (salarin and salmon kininogen) in Atlantic salmon, Salmo salar.

Tissue localization of cysteine proteinases (cathepsins) and their inhibitors (salarin, salmon kininogen) was performed in tissues of the Atlantic salmon. In skin, both epidermis and dermis were strongly stained by antisera against salarin and salmon kininogen. In epidermis the intercellular space seemed to be heavily stained (salarin). In kidney, the inhibitors were mainly localized to the interstitial capillaries. Also, some epithelial cells of the tubules (salarin) and some cells of the interstitium were stained. Mostly, the staining had a diffuse cytoplasmic localization. In the liver some hepatocytes were strongly positive for salarin and salmon kininogen. Purified fish cysteine proteinase inhibitors were not found to inhibit the growth of fish pathogenic bacteria and viruses. In the trunk kidney cathepsins B and L were localized in epithelial cells of the tubules (proximal part) and in cells of the interstitium. Mostly, the staining showed a prominent lysosomal localization. In head kidney large macrophage-like cells were positively stained for cathepsin B. The staining was localized to granula/vacuoles in the cytoplasm. In the liver, some hepatocytes were strongly stained and some were less strongly positive for cathepsin B and L. Mostly, the hepatocytes showed lysosomal staining. Cathepsin L was found in some big macrophage-like cells in the spleen. Mucosal epithelial cells of the esophagus and intestine seemed to be strongly stained for cathepsin B and L. The results show that cathepsins and their inhibitors are specifically and widely distributed in the Atlantic salmon skin indicating that they perform some biologically important and specific but so far unknown functions.