Role of temperature in regulating timing of germination in soil seed reserves of Lamium purpureum L.

Fresh seeds of Lamium purpureum L. were dormant at maturity, and when buried and exposed to natural seasonal temperature changes they exhibited an annual dormancy/non-dormancy cycle. During burial in summer, fresh seeds and those that had been buried for 1 year afterripened and thus were non-dormant by September and October; light was required for germination. During autumn and winter seeds re-entered dormancy, and during the following summer they became non-dormant again. Dormant seeds afterripened when buried and stored over a range of temperatures, becoming conditionally dormant at low (5, 15/6°C) and non-dormant at high (20/10, 25/15, 30/15 and 35/20°C) temperatures. Conditionally dormant seeds germinated to high percentages at 5, 15/6 and 20/10°C, while non-dormant seeds germinated to high percentages additionally at 25/15, 30/15 and 35/20°C. Low temperatures caused non-dormant seeds to re-enter dormancy, while high temperatures caused a sharp decline in germination only at 30/15 and 5°C. The temperature responses of L. purpureum seeds are compared to those of L. amplexicaule L.     

Warfarin in the dog: pharmacokinetics as related to clinical response

Warfarin was administered intravenously (i.v.) as a single dose of 1.5 mg/kg to healthy dogs and the pharmacokinetic parameters were investigated. Elimination could be described by a one-compartment open model. Values for the elimination half-life and apparent specific volume of distribution were 14.5 ± 4.1 h and 0.22 ± 0.04 litre/kg, respectively. Oral maintenance doses were calculated from the data collected following i.v. administration and administered every 12 h for a total of five doses after an initial i.v. loading dose of 1.5 mg/kg. Prothrombin times increased from a control value of 8.6 ± 0.3 sec to 55.2 ± 5.2 sec over a period of 96 h. Prothrombin time returned to control values by 62 h after withdrawal of the drug. We propose a dosage regimen of warfarin for anticoagulant therapy in the dog of 0.22 mg/kg to be given orally every 12 h. Prothrombin time should be monitored during therapy and the dose of warfarin modified according to the degree of suppression of coagulation factors desired.     

Epidemiology and Clinical Features of Dermatophytosis in Dogs and Cats at Louisiana State University: 1981–1990

Abstract— Dermatophytes were cultured from seventy of 1824 (3.8 per cent) canine samples and 61 of 408 (14.9 per cent) feline samples submitted over ten years. Microsporum canis was the most common species isolated (86/131). M. gypseum (31/70) and M. canis (30/70) were isolated most frequently from dogs whereas M. canis was isolated most frequently from cats (56/61). Both male and female dogs and cats were equally affected by dermatophytosis. There was a higher incidence in both dogs and cats less than one year of age. Mixed breed dogs (19/70), domestic shorthaired cats (39/61) and Persian cats (15/61) were most often affected. M. gypseum had a greater incidence of infection in summer and most often caused localized disease in dogs. In dogs, localized dermatophytosis was more common. Localized infections were most often caused by M. canis in all animals, with the head (23/75), feet (10/75) and tail (7/75) affected most frequently. Résumé— Dos dermatophytes ont été isolés à partir de 70/1824 (3,8 pourcent) prélèvements canins et 61/408 (14,9 pourcent) prélèvements félins collectés sur une période de dix ans. L'espèce la plus souvent isolée était Microsporum canis (86/131). Microspomm gypseum (31/70) et M. canis (30/70) étainet les plus fréquemment isolés chez les chiens, alors qu'il s'agissait de M. canis (56/61) chez les chats. Les mâles et les femelles, chiens ou chats, étaient également représentés. Il y avait une nette incidence des animaux de moins d'un an, tant chez les chiens que chez les chats. Les chiens croisés (19/70), les chats européens (39/61) et les chats Persans (15/61) étaient les plus souvent atteints. L'incidence de M. gypseumétait plus importante l'été et provoquait les plus souvent des lésions localisées les chiens. Les formes localisées étaient plus fréquentes chez les chiens et le plus souvent dues àM. canis dans les deux espèces, avec une atteinte préférentielle de la tête (23/75), des membres (10/75) et de la queue (7/75). Zausammenfassung— Aus siebzig von 1824 Proben von Hunden (3,8 Prozent) und 61 von 408 Proben von Katzen (14,9 Prozent) von einem Zeitraum über zehn Jahre wurden Dermatophyten angezüchtet. Microsporum canis war die am häufigsten isolierte Spezies (86/131). Microsporum gypseum (31/70) und M. canis (30/70) wurden am häufigsten bei Hunden isoliert, M. canis dagegen wurde am häufigsten bei Katzen isoliert (56/61). Männliche wie weibliche Hunde und Katzen waren gleichermaßen von Dermatomykosen betroffen. Sowohl bei Hunden also auch bei Katzen war die Inzidenz bei Tieren unter einem Jahr höher. Am häufigsten erkrankten Mischlingshunde (19/70), Kurzhaarhauskatzen (39/61) und Perserkatzen (15/61). Die Inzidenz der Infektion mit M. gypseum war im Sommer größer, bei Hunden verursachte es mehr lokalisierte Erkrankungen. Bei Hunden überhaupt waren lokalisierte Dermatomykosen häufiger anzutreffen. Lokalisierte Infektionen wurden bei alien Tieren am häufigsten durch M. canis verursacht, am meisten betroffen waren Kopf (23/75), Pfoten (10/75) und Schwanz (7/75). Resumen Se cultivaron dermatofitos de setenta de 1824 (3,8 por ciento) muestras caninas y 61 de 408 (14,9 cor ciento) muestras felinas, sometidas durante diez anos. Microsporum canis fue la mas común de las especies aisladas (86/131). Microsporum gypseum (31/70) y M. canis (30/70) se aislaron mas frecuentemente de perros, mientras que M. canis fue aislado con más frecuencia de gatos (56/61). Ambos, macho y hembra, perros y gatos fueron igualmente afectados por la dermatofítosis. Había una mayor incidencia en perros y gatos menores de un año de edad. Perros de cruce de razas (19/70), gatos domésticados de pelo corto (39/61) y gatos persas (15/61) fueron afectados con más frecuencia. M. gypseum tenía una mayor incidencia de infección en verano, y muy frecuentemente causaba enfermedades localizados en perros. En perros, fue más commún la dermatofitosis localizada. Infecciones localizadas eran más frecuentemente causadas por M. canis en todos los animates, con la cabeza (23/75), pies (10/75) y rabo (7/75) afectados con más frecuencia.     

Tissue distribution of tetraethylammonium (TEA) in dogs and goats

The tissue distribution of tetraethylammonium (TEA), a highly polar drug which does not undergo biotransformation, was studied in intact and nephrectomized dogs and goats. Values for β, the overall elimination rate constant, were significantly reduced by nephrectomy but species differences were not significant. Values for apparent specific volume of distribution (V'_d) were unexpectedly large and tissue to plasma ratios were 4.0 and 5.0 in the nephrectomized goat and dog, respectively. The distribution of TEA to various tissues followed closely the expected pattern of regional blood flow, although TEA attained concentrations in liver, heart, lungs and viscera in excess of the concentration in the plasma.     

Procainamide in the dog: antiarrhythmic plasma concentrations after intravenous administration

Procainamide hydrochloride was administered to ouabain-intoxicated dogs to determine an antiarrhythmic plasma concentration of procainamide. Ventricular arrhythmias were produced in dogs following intravenous injections of ouabain. After a sustained ventricular tachycardia was achieved, procainamide was administered and plasma samples collected for assay. Plasma procainamide was assayed by fluorescence polarization immunoassay. Procainamide was administered at increasingly higher constant rate infusions in order to achieve intermittent, steady-state plasma concentrations. Infusion rates were calculated on the basis of previous pharmacokinetic information. All six dogs that received procainamide converted to a normal sinus cardiac rhythm after attaining a mean plasma concentration of 33.8 micrograms/ml with a range of 48.5 micrograms/ml-25.0 micrograms/ml. It was observed that the computer-generated prediction of plasma concentrations based upon previous pharmacokinetic data produced an underestimate of the actual plasma concentrations. These data may suggest that plasma concentrations of procainamide for controlling some cardiac arrhythmias in dogs may be higher than plasma concentrations cited for human patients.     

Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis

Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid‐trophic levels. The east–west asymmetry of the oceanic response to climate forcing after 1976–77 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad‐scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open‐ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades.