Alleviation of postanesthetic hypoxemia in the horse

This study was designed to investigate the effect of the nasotracheal insufflation of oxygen at a flow rate of 15 L/min on the arterial partial pressure of oxygen during the recovery period following inhalation anesthesia in the horse. It has been stated that this is a suitable flow rate to prevent postoperative hypoxemia but without any experimental evidence to support those statements. Horses being used for the study of healing of cartilage were anesthetized on two separate occasions. Following one period of anesthesia they were allowed to recover breathing room air, and following the other period of anesthesia oxygen was insufflated into the trachea at 15 L/min throughout the recovery period. This permitted each horse to act as its own control and allowed statistical analysis using Student's t-test for paired samples.

The insufflated horses had a higher arterial partial pressure of oxygen during the recovery period than did the noninsufflated horses (p < 0.05).

     

Mycoplasma (M.) bovis antiserum "Dessau"--a diagnostic material for the identification of M. bovis

Mycoplasma bovis antiserum "Dessau" was used to investigate 4,553 mycoplasma strains, between 1985 and 1987, using a method described elsewhere. This diagnostic Agent is successfully used at present at all Regional Institutes of Veterinary Services throughout the GDR.     

Effects of triazole fungicides on sterol biosynthesis during spore germination of Botrytis cinerea,Venturia inaequalis and Puccinia graminis f. sp. tritici

With three plant pathogens,Botrytis cinerea, Venturia inaequalis and Puccinia graminis f. sp.tritici, the time course of sterol biosynthesis during spore germination was examined by labeling experiments along with the question whether this pathway could be inhibited by triazole fungicides. Conidia ofB. cinerea andV. inaequalis are able to synthesize sterols immediately after the beginning of the germination process when the germ tubes have not yet emerged. On the contrary uredospores ofP. graminis start sterol biosynthesis after 6 to 8 h germination time almost at the end of the germ tube phase, indicating that sterol reserves of the spores are likely to be used for the germ tube growth.The sterol C-14 demethylation appeared to be the rate limiting step within the sterol biosynthetic pathway: the half life of 24-methylenedihydrolanosterol was less than 1 h forB. cinerea. It was more than 1 h forV. inaequalis and 3 h forP. graminis. Independent of these differences in the time course of sterol biosynthesis and in the C-14 demethylation rate, the synthesis of sterols in germinating spores was strongly inhibited by triazole fungicides in all three pathogens examined. In contrast toP. graminis, this inhibition could be demonstrated withB. cinerea andV. inaequalis even in ungerminated conidia, indicating that the fungicides were rapidly taken up and reached their target within 1 or 2 h. These results are discussed along with the question whether spore germination can be used as a bioassay for the estimation of sensitivities of triazole fungicides.     

Colonization of rose by Sphaerotheca pannosa (Wallr.) Lév. var. rosae Wor.

Colonization of rose by powdery mildew (Sphaerotheca pannosa) is described in terms of mycelium growth, conidiophore production and sporulation in time. The data used are gathered during different years, put together and treated by means of graphic models. Colonies could be separated into fast and slow growing colonies. Colonies initiated on leaves of increasing age showed a decreasing growth rate. Production of conidiophores and conidia started on the same day, and the relative activity of conidiophore production reached its maximum 6 days after the end of the latency period, followed 1 day later by the maximum activity of conidium production. Both conidiophore and conidium production continued for a long time at a low level. The effect of leaf age on conidiophore production found expression in differences in production rate during the first days of colony development and in final production levels. Observations on naturally infected leaves in an outdoor experiment showed a rapid decrease of sporulation on leaves of 10 days and older. Highest percentages of sporulating leaf area were observed on leaves between 7 and 10 days old.