Failure of a Subunit Bovine Herpesvirus 1 Vaccine to Protect Against Experimental Respiratory Disease in Calves

In two experiments in which 31 calves were used, a bovine herpesvirus 1 subunit vaccine previously shown to elicit a strong immunological response in adult cattle failed to do so in younger animals and failed to protect against pneumonia caused by sequential exposure to virulent bovine herpesvirus 1 and Pasteurella haemolytica aerosols. One of the experimental groups had been previously inoculated with a live commercial vaccine but even this failed to elicit a strong immunological response. These results indicate that the calves were in a refractory state when immunized and may explain why similar vaccine failures occur in the field.     

Viral infections of the respiratory tract of calves: Local immunity

Local immunity is the first defence mechanism against viral respiratory infections in young calves. The great variety of different viruses which may infect the very young animal makes it necessary to develop effective local defences early in life. The best approach appears to be to increase the subjects' defences by using immunoadjuvants and interferon inducers. With this end in view we should increase our knowledge of the immune system of the calf respiratory tract, particularly with respect to specific immunoglobulins, and cells which mediate the immune response.

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Kurzfassung Die örtliche Immunität ist der erste Abwehrmechanismus gegen virale Erkrankungen der Atemwege beim jungen Kalb. Da sich diese sehr jungen Tiere mit den unterschiedlichsten Viren infizieren können, ist ein frühzeitiger Aufbau einer wirksamen örtlichen Abwehr unerlässlich; dieses Problem liesse sich vielleicht durch eine Steigerung der Abwehrkräfte bei den Tieren mit Immunitatsadjuvanten und Induktoren von Interferonbildung bewältigen. Die bisher vorliegenden Angaben über das Immunsystem der Atemwege beim Kalb (spezifische Immunglobuline, Immunzellen) müssen zu diesem Zweck noch vertieft werden.

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Resume L'immunité locale est le premier mécanisme de défense contre les affections réspiratoires virales du jeune veau. La grande diversité des virus pouvant infecter ces sujets très jeunes rend indispensable l'établissement précoce de défenses locales éfficaces; l'augmentation des défenses des sujets par l'emploi d'adjuvants de l'immunite et d'inducteurs d'interféron semble être le moyen d'aborder ce problème. Les données que nous possédons sur le système immunitaire de l'appareil réspiratoire du veau (immunoglobulines specifiques, cellules effectrices de l'immunité) doivent, dans ce but, être approfondies.

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Riassunto L'immunita locale e il primo meccanismo di difesa del giovane vitello contro le affezioni virali delle vie respiratorie. La grande diversità dei virus in grado di infettare soggetti molto giovani rende necessaria l'instaurazione precoce di difese locali efficaci; la soluzione migliore dovrebbe consistere nel potenziamento delle difese dei soggetti mediante adiuvanti dell'immunità e induttori di interferon. A tal fine e necessario approfondire i dati in nostro possesso sul sistema immunitario dell'apparato respiratorio del vitello (Immunoglobuline specifiche, immunociti).

     

Cinosulfuron: chemical and biological degradability, adsorption and dissipation in flooded paddy field sediment

Cinosulfuron is a sulfonylurea herbicide largely used in the extensive cultures of flooded rice in North Italy. The degradation of cinosulfuron has been investigated in sterile aqueous solutions at 30 degrees C at different pH values. It was rapidly degraded at acidic pH (half-lives 3, 9 and 43 days at pH 4, 5 and 6, respectively) while the half-life was > 1 year at pH 7 and 9. Two degradation products formed by cleavage of the sulfonylurea bridge were identified by LC-MS. Degradation by selected mixed microbial cultures tested in aerobic and anaerobic conditions was very slow and attributable to chemical hydrolysis due to the acidic pH of the cultural broths. Degradation took place in freshly collected rice field water treated for two years with cinosulfuron but, in this case also, chemical hydrolysis prevailed over microbial degradation. In contrast, in flooded sediment simulating the paddy field environment, the dissipation rate of cinosulfuron was higher than expected from chemical hydrolysis according to the pH of the system, indicating the involvement of soil microflora. Although the herbicide exhibited a reduced affinity for the sediment surfaces demonstrated by the low value of the K(f) Freundlich coefficient (0.87 on a micromolar basis), the rapid dissipation observed in the simulated paddy field should prevent its leaching to ground water.     

Prevalence of ulcers of the squamous gastric mucosa in standardbred horses

This study was performed to determine the prevalence of ulcers in the gastric squamous mucosa in Standardbred racehorses. Observations were performed at monthly intervals between the beginning of their training season and their 1st qualifying race. This study also identified risk factors at different levels of race training. Forty-eight Standardbred racehorses from 3 training stables in Quebec, Canada, were studied. Baseline historical information and gastroscopic findings were recorded at the beginning of the trial, and once a month thereafter, between December 2001 and June 2002, until the horse's 1st qualifying race or the end of the training. Intensity of training ranged from jogging to intensive training just before the 1st race and was assigned an ordinal score. Location of squamous ulcers and their appearance were observed on gastroscopy, and an ordinal score was assigned. Prevalence of squamous ulcers from the 2nd through the 4th month (72-88%) of training remained at a significantly higher level (P = .002 to .04) than at the onset of the study (38%) and was also higher in intensely trained horses than in joggers (93% versus 56%). Moderate or more intensive training increased the odds (odds ratio [OR], 3.39; confidence interval [CI], 1.34-8.56; and OR, 11.4; CI, 3.21-40.5, respectively) of detecting ulcers with higher scores. These odds were also higher in trotters (OR, 2.17; CI, 1.07-4.43) than in pacers and generally increased with the duration of training. Duration of training, training level, and gait type also influenced the number of sites with ulcers in the same way. Ulcers had higher scores along the lesser curvature (LC) and the margo plicatus (MP) areas of the stomach. It was concluded that squamous ulcers appeared early in the training of Standardbred racehorses, that the number of sites affected and the ulcer score are related to the intensity of training, and that trotters are more prone to squamous ulcers than pacers.     

Exploration of the cellular mediated immunity by the blastogenesis test during chronic brucellosis in human

The diagnosis of the chronic, human brucellosis is frequently difficult and usually needs experimental methods. This paper describes a lymphocyte stimulation test with a Brucella antigen and the results of this test concerning 45 brucellic or not brucellic patients. It is concluded that this test is interesting, especially for the chronic and sero-negative Brucellosis diagnosis.