STUDIES ON THE GROWTH OF SEEDLINGS OF AGROPYRON REPENS (L.) BEAUV AND AGROSTIS GIGANTEA ROTH.

Summary. The growth of seedlings of Agropyron repens (L.) Beauv. and Agrostis gigantea Roth, in pots was studied in two experiments in 1968 and 1969. In Experiment 1 their growth was compared with that of wheat and in Experiment 2 they were grown in sandy loam (Woburn) and silt loam (Rothamsted) soil at four levels of nitrogen. Both species grew faster than wheat, mainly because they had a larger leaf area ratio. Tillering began earlier in wheat, but continued longer in the grasses, which eventually had many more shoots. Ears emerged in the order: wheat before Agropyron before Agrostis. Although Agrostis had much lighter seeds than Agropyron, it grew faster, but Agropyron initiated rhizomes sooner, usually when it had 1–2 tillers and 4 leaves. Agrostis did not initiate rhizomes until it had at least 10 tillers and 6 leaves. In Experiment 2 the seedlings at first grew more in Woburn than in Rothamsted soil but later more in Rothamsted than in Woburn soil. There was no evidence of a species/soil interaction but nitrogen had more effect on both species in Woburn than in Rothamsted soil. Neither soil type nor nitrogen affected the time at which rhizomes were initiated. Etude de la croissance de plantules d'Agropyron repens (L.) Beauv. et d'Agrostis gigantea Roth. Résumé. La croissance de plantules A'Agropyron repens (L.) Beauv. et d'Agrostis gigantea Roth, cultivdes en pots a étéétudiée au cours de deux expériences en 1968 et 1969. Dans la premiére experience, leur croissance fut compareée à celle du blé et dans une seconde experiénce, ces deux espéces furent cultivées sur un sol sablo-limoneux (Woburn) et sur un sol argilo-limoneux (Rothamsted) á quatre niveaux d'azote. Les deux mauvaises herbes poussérent plus vite que le blé, principalement en raison de leur rapport plus éalevé de surface foliaire. Le tallage commenga plus tot chez le bié, mais se poursuivit plus longtemps chez les deux mauvaises herbes qui, en fin de compte, eurent plus de tiges. L'épiaison se produisit dans l'ordre suivant: bléa, Agropyron, Agrostis. Bien que I'Agrostis ait des semences plus petites que I'Agropyron, il poussa plus vite, mais I'Agropyron émit des rhizomes plus tôt, habituellement au stade 1 à 2 talles et 4 feuilles. L'Agrostis n'émit pas de rhizome avant d'atteindre au moins le stade 10 talles et 6 feuilles. Dans la deuxième experience, les plantules poussérent d'abord plus dans le sol de Woburn que dans celui de Rothamsted mais, plus tard, plus dans le sol de Rothamsted que dans Celui de Woburn. II ne fut pas décelé d'interaction entre le sol et les espéces, mais I'azote fit un effet plus marqué sur les deux espéces dans le sol de Woburn que dans celui de Rothamsted. Ni le type de sol, ni le niveau d'azote n'eurent d'influence sur l'époque à laquelle les rhizomes commencérent de croître. Untersuchungen zum Wachstum von Keirnpjlanzen von Agropyron repens (L.) Beauv. Und Agrostis gigantea Roih. Zusammenfassung. Das Wachstum von Keimpfianzen von Agropyron repens (L.) Beauv. und Agrostis gigantea Roth, in Töpfen wurde 1968 und 1969 in zwei Versuchen untersucht. In Versuch II wurde das Wachstum mit dem von Weizen verglichen. In Versuch II wurden sie in sandigen Lehmboden (Woburn) und Silt-Lehm-(Rothamsted) Boden bei vier Stickstoffstufen angezogen. Beide Arten wuchsen in erster Linie wegen ihres grösseren Blattflächenanteils schneller als Weizen. Die Bestockung begann fruher bei Weizen, zog sich jedoch bei den Gräsern, die schliesslich wesentlich mehr Halme hatten, langer hin. Ahrenschieben erfolgte am frühesten bei Weizen, dann bei Agropyron und schliesslich bei Agrostis. Obgleich Agrostis viel leichtere Samen hatte als Agropyron, wuchs es schneller, doch entwickelte Agropyron fruher Rhizome, nornialerweise bei 1–2 Bestockungstriebe und 4 Blättern. Agrostis entwickelte Rhizome nicht ehe es mindestens 10 Bestockungstriebe und 6 Blätter hatte. In Versuch II wuchsen die Keimpflanzen zunächst besser in Woburn- als in Rothamsted-Boden, später wieder besser in Rothamsted als in Woburn-Boden. Es gab keine Anhalts-punkte für eine Interaktion zwisehen den Arten und dem Boden, doch wirkte Stickstoff bei beiden Arten besser in Woburn- als in Rothamsted-Boden. Weder Bodentyp noch Stickstoffmenge beeinflussten den Beginn der Rhizombfldung.     

Partial Resection and Omentalization: A New Technique for Management of Prostatic Retention Cysts in Dogs

Objective- The purpose of this study was to determine the results of a new technique for management of prostatic retention cysts in dogs.
Study Design- A retrospective clinical study.
Animals- Eighteen client-owned dogs.
Methods- Dogs with prostatic retention cysts were treated by celiotomy and drainage of the cysts. The majority of the cyst wall was resected and residual cyst cavities were packed with omentum. All dogs were castrated.
Results- Long-term resolution of clinical signs was achieved in all dogs, with follow-up periods ranging from 6 to 42 months. Five dogs developed urinary incontinence postoperatively. This persisted in two dogs, but was well controlled with phenylpropanolamine. In the remaining dogs, the incontinence was transient and resolved within 2 months of surgery.
Conclusions- Partial cyst resection combined with omentalization and castration was a simple and effective means of managing prostatic retention cysts. The incidence of serious complications, including postoperative urinary incontinence, was low.     

Effect of non-linear plasma protein binding on unbound and total plasma phenylbutazone concentrations in cows

Boudinot, F.D., Williams, R.J. & Smith, J. A. Effect of non-linear plasma protein binding on unbound and total plasma phenylbutazone concentrations in cows. J. vet. Pharmacol. Therap. 13, 132–136.
The influence of plasma protein binding on unbound and total phenylbutazone concentrations in cows was examined employing data from the literature. Protein binding parameters (number of binding sites and affinity constants) were generated by computer analysis to characterize the concentration-dependent plasma protein binding of phenylbutazone. Unbound plasma phenylbutazone concentrations were calculated from total plasma drug concentrations observed after administration of a single dose of phenylbutazone to cows. Pharmacokinetic parameters for unbound phenylbutazone were obtained. Parameters characterizing die plasma protein binding and pharmacokinetics of unbound phenylbutazone derived from single-dose administration were then used to predict unbound and total drug concentrations after multiple-dose administration of phenylbutazone. Total plasma phenylbutazone concentrations predicted from single-dose pharmacokinetic parameters agreed well with observed values following multiple-dose administration of the drug. Thus, the results of this analysis demonstrate that the non-linear pharmacokinetics of phenylbutazone in the cow can be attributed to the concentration-dependent plasma protein binding of the drug.
F. Douglas Boudinot, Department of Pharmaceutics, College of Pharmacy, University of Georgia, Athens, GA 30602, USA.