Serum pharmacokinetics of oxytetracycline in sheep and calves and tissue residues in sheep following a single intramuscular injection of a long-acting preparation

The pharmacokinetics of a long‐acting oxytetracycline (OTC) formulation (Liquamycin® LA‐200®) injected intramuscularly (i.m.) at a dose of 20 mg/kg were determined in four calves and 24 sheep to determine if the approved label dose for cattle provided a similar serum time/concentration profile in sheep. The AUC for the calves was 168±14.6 (μg ? h/mL) and was significantly less than the AUC for sheep (209±43 μg ? h/mL). Using the standard two‐stage approach and a one‐compartment model, the mean Cmax for the calves was 5.2±0.8 μg/mL, and for the sheep was 6.1±1.3 μg/mL. The mean terminal phase rate constants were 0.031 and 0.033 h, and the Vdss were 3.3 and 3.08 L/kg for the calves and sheep respectively. Analysis of the data using the standard two‐stage approach, the naive pooled‐data approach and a population model gave very similar results for both the cattle and sheep data. Sheep tissue residues of OTC in serum, liver, kidney, fat, muscle and injection site were measured at 1, 2, 3, 5, 7 and 14 days after a single i.m. injection of 20 mg/kg OTC. Half‐lives of OTC residues in the tissues were 38.6, 33.4, 28.6, 25.4, 21.3, and 19.9 h for injection site, kidney, muscle, liver, mesenteric fat and renal fat, respectively. The ratio of tissue to serum concentration was fairly consistent at all slaughter times, except for the fat and injection sites. The mean ratios were 1.72, 4.19, 0.11, 0.061, 0.84 and 827 for the liver, kidney, renal fat, mesenteric fat, muscle and injection sites, respectively. The tissue concentrations of OTC residues were below the established cattle tolerances for OTC in liver (6 p.p.m.), muscle (2 p.p.m.) and kidney (12 p.p.m.) by 48 h, and in injection site muscle by 14 days after the single i.m. injection of 20 mg/kg.     

Vergleich von Nachweismethoden für Kartoffelzystennematoden (Globodera spp.) im Hinblick auf eine Qualitätssicherung von Diagnosen geregelter Schadorganismen

Testing for PCN is indispensable in EC seed potato production, to avoid a further spread or introduction of this pest. Till now methods for sampling and detection are varying between member states and even within Germany. Therefore in order to obtain comparable results within a new PCN directive the procedure will be regulated by EPPO standard diagnostic protocols, like it is the case for testing Globodera spp. resistance of potato varieties. The Bavarian plant protection service hopes, that beside cyst extraction by flotation the bioassay will be part of the new EPPO standard. The bioassy – in contrast to PCR methods – is well established and allows a reliable discrimination not only of PCN species but also of races and pathotypes. Results of a long-time survey demonstrate clearly, that bioassay and cyst extraction yield comparable results provided quality assurance criteria are met.     

A comparison of RNA concentrations and ornithine decarboxylase activity in Atlantic salmon (Salmo salar) muscle tissue,with respect to specific growth rates and diel variations

RNA concentrations and enzyme activities are often used as indices of recent growth in fish, but few studies have used both methods to assess the same fish. This study measured RNA concentrations and ornithine decarboxylase (ODC) activity in muscle tissue of juvenile Atlantic salmon (Salmo salar) to compare their usefulness for reflecting specific growth rates, and to determine whether either growth index was influenced by diel variations or time of feeding. Three groups (n = 54 in total) were fed 1.5% of body weight in commercial pellets in four feedings per day. One group was fed only in the morning (0830–1230h), one in the afternoon (1430–1830h), and one in the morning and afternoon (0830–1830h). At the end of ten days, fish were sampled at three times (0130h, 1030h, 1630h) over a single 24h period. Correlations to specific growth rate were slightly higher for RNA concentrations than for ODC activity, but both were highly significant. RNA and ODC activity were also correlated to each other. These results suggest that RNA concentration and ODC activity, taken together, can be used to monitor changes in both the numbers and activity of ribosomes. For RNA concentrations, there was no evidence of an effect of diel variations or the time of feeding. For ODC activity, a significant diel effect (all feed schedules combined) was detected if one non-growing fish was excluded from the analysis; activity of the enzyme was slightly higher in the sample taken at night (0130h) than in the two daytime samples. Contribution no. 8, Catamaran Brook Habitat Research Project     

Improved bondability of wax-treated wood following plasma treatment

In this study, the impact of a plasma treatment using dielectric barrier discharge at atmospheric pressure on wax-treated beech was investigated by surface energy determination and adhesion tests. Measurements of the surface energy revealed a strong increase in surface polarity along with increased surface energy as a result of the plasma treatment, pointing to increased adhesion properties. To evaluate the adhesion properties of a polyvinyl acetate (PVAc) adhesive on beech treated with montan ester wax and synthetic Fischer–Tropsch wax, a special peel test was applied. This peel test provided evidence of increased adhesion of the PVAc after plasma treatment of both materials investigated.     

Untersuchungen an den Nervi optici and an den Gehirnen von Schafen mit Mikrophthalmie

Inhalt An 6 Schafen mit angeborener Mikrophthalmie wurden morphologische und histologische Untersuchungen an der Sehbahn im Bereich des Dienzephalons durchgeführt and die Befunde mit denen bei 3 Kontrolltieren verglichen. Die Tracti optici der Probanden sind umfangsvermindert. Die Corpora geniculata lateralia sind umfangsvermindert and flach. In den Nuclei dorsales ist der schichtenförmige Aufbau nur undeutlich ausgebildet. Die Zelldichte variiert in den einzelnen Schnittebenen. An den Nervenzellen lassen sich verschiedenartige zytologische Veränderungen feststellen. Die Colliculi anteriores und die Brachia colliculi anterium sind deutlich verkleinert. Histologische Veränderungen sind auf das Stratum zonale und das Stratum cinereum beschränkt und durch eine erhöhte Zelldichte und eine unregelmäβige Zellverteilung gekennzeichnet. Die Colliculi posteriores erscheinen vergröβert. Die Ursprungskerne des Nervus oculomotorius weisen keine Veränderungen auf. Contents Investigations on the optic nerves and brains of microphthalmic sheep. Communication II: Report on the optic nerves in the area of the diencephalon. Morphological and histological experiments on the visual tract in the area of the diencephaton were carried out on 6 sheep with congenital microphthalmia. The Results were compared with 3 control animals. The corpora geniculata lateralia of experimental animals were smaller in circumference. The laminated structure of the nuclei dorsales did not clearly develop, the number of cells per unit area varied in the individual sections and the nerve cells revealed a variety of cytological changes. The colliculi anteriores and the brachia colliculi anterium were clearly smaller. Only the stratum zonale and the stratum cinereum revealed histological changes. These were characterized by an in-crease in the number of cells per unit and an irregular cell distribution. The colliculi posteriores appeared enlarged. The nuclei at the origin of the nervus oculomotorius remained unchanged.