Pathological findings in the bulbourethral glands of bulls

The bulbourethral glands of 323 Bos indicus or B. indicus crossbred bulls more than 1 1/2 years old were examined in an abattoir study. Bulbourethral adenitis was diagnosed grossly and confirmed by histological examination in 4 (1.2%). Unilateral chronic interstitial inflammation was seen in 2 cases; one of these was associated with a degenerative-type seminal vesiculitis. In the others adenitis was bilateral; in one case it was associated with a concretion and foreign (plant) material in the principal duct of the left bulbourethral gland; in the other bilateral case, numerous calculi were present and microscopically, a chronic active and diffuse inflammation was observed. Chemical analysis of the calculi showed calcium oxalate and tricalcium phosphate to be the most important components. Corynebacterium spp was isolated from the lesion with multiple calculi but attempts to isolate Chlamydia spp, Mycoplasma spp and Brucella abortus from the 4 adenitis cases were unsuccessful. Congenital abnormalities such as glandular fusion (2.2%) or unilateral aplasia (0.6%) were also observed. Cysts were the most common finding (19.2%), and duct dilation was frequent (7.1%). The significance of these findings in relation to fertility is considered.     

A more sensitive technique for isolating infectious pancreatic necrosis virus from asymptomatic carrier rainbow trout, Salmo gairdneri Richardson

Abstract. An improved technique for isolating infectious pancreatic necrosis virus (IPNV) is described. It involves trypsinization of the suspect tissue, separation of the trypsinized cells and their co-cultivation with indicator RTG-2 cells. This co-cultivation method is compared with homogenization, followed by membrane filtration, a procedure routinely employed by most disease diagnostic laboratories. From the two IPN-infected farms studied, IPNV could be isolated by homogenization from only 50 and 66%, respectively, of the fish from which virus was detected by co-cultivation. This difference in sensitivity can be explained in two ways, viz: (a) some of the virus is being retained by the membrane filter during filtration to remove contaminants following homogenization; (b) the presence of neutralizing factors in the tissue homogenate are neutralizing the virus and thus no cytopathic effect ensues. No correlation between serum neutralizing antibody levels and the differences in sensitivity of the two methods was found. The co-cultivation method is as practical as, and certainly no more time-consuming than, the homogenization technique.     

64‐MULTIDETECTOR COMPUTED TOMOGRAPHIC ANGIOGRAPHY OF THE CANINE CORONARY ARTERIES

Canine coronary artery angiography (CTA) was performed in four anesthetized healthy dogs using 64‐multidetector computed tomography. Esmolol, a β‐1 adrenergic receptor antagonist, and sodium nitroprusside, an arteriolar and venous dilator, were administered to enhance visualization of the coronary arteries by reducing heart rate and creating vasodilation. The left main coronary artery with its three main branches and the right coronary artery were visualized and subdivided in 13 segments for evaluation. Optimal reconstruction interval, expressed as percentage of the R‐to‐R interval, was determined at 5% in 2.9%, 35% in 1%, 75% in 21.2%, 85% in 43.3%, and 95% in 31.7% of the segments. Overall image quality was good in 41.3% of the segments and excellent in 14.4%. There was blur in 98.1%, motion in 17.3%, and stair step in 6.7% of the evaluated segments, but these artifacts did not interfere with anatomic depiction of the arteries. Cross‐sectional anatomy of the coronary arteries as evaluated from the coronary CTA agreed well with gross anatomic evaluation and published information. The use of esmolol did not lead to the target heart rate of 60–65 beats/min. Nitroprusside had no significant effect on visualized length or diameter of the coronary artery branches. Coronary CTA is useful for the anatomic depiction of coronary artery branches in the dog.     

Variation in host range, systemic infection and epidemiology of Leptosphaeria maculans

The A and B groups (aggressive and non-aggressive) of Leptosphaeria maculans were compared in studies of host range, infection phenotypes and epidemiology. Isolates of both groups infected a wide range of cruciferous hosts including Brassica napus, B. rapa, B. oleracea, B. juncea, B. carinata. B. nigra, Thlaspi arvense and Raphanus sativus. On cotyledons, B-group isolates were generally more aggressive than A-group isolates, causing local lesions and subsequent systemic invasion of the majority of test species. On susceptible stems, A-group isolates caused cortical lesions; B-group isolates, if they reached the stem, usually caused pith lesions with no external symptoms. In a susceptible line of B. napus , CrGC5, systemic infections of the leaf and petiole were similar with both groups, but the B-group rarely entered the stem to form cortical lesions or cankers. At two different field locations, natural epidemics caused by the two groups on oilseed rape leaves were similar in overall pattern, B-group lesions occurred slightly later but the incidence increased more rapidly and reached a maximum slightly earlier than that of the A group. The two groups differed markedly in stem infection patterns. Infection of the cortex near the base of the stem and the development of a typical stem canker was caused entirely by the A group. However the B group often caused considerable damage to the pith. Superficial chlorotic lesions on stems and inflorescences were mainly attributable to the B group. In view of the stem pith infection by the B group without external symptoms, its importance on oilseed rape may have been underestimated previously.     

Performance studies with the new anticoagulant rodenticide,flocoumafen, against Mus domesticus and Rattus norvegicus1

Flocoumafen is a new, highly potent anticoagulant rodenticide from Shell Research. It is effective against all the economically important species tested to date, including those with warfarin-resistant strains. This paper is concerned with its performance against two important commensal rodent species, Mus domesticus and Rattus norvegicus. In laboratory studies these two pest species may absorb a lethal dose of flocoumafen by taking a 0.005% (50 ppm) bait as part of their food intake on only one occasion. This single-feed potency of flocoumafen, combined with its good intrinsic palatability, makes it ideal for use in pulse baiting. Marketed under the Shell trade mark Storm, the principal bait formulation selected for commercialization is the wax-bound block. Recent advances in formulation development include increased resistance to attack by insects and fungi and the incorporation of a bitter taste which acts as a deterrent for humans without influencing the palatability of the bait to rodents. Flocoumafen's outstanding potency has been confirmed in a wide range of field trials. In the UK alone, almost 70 pen and field trials have been successfully completed with a mean estimated control in excess of 95%.     

Identification and expression of the gene Yr2 for resistance to Puccinia striiformis in the wheat differential cultivars Heines Kolben, Heines Peko and Heines VII

Genetic data showed that a common gene was present in the three differential wheat cultivars Heines VII ( Yr2 ), Heines Peko ( Yr2, Yr6 ) and Heines Kolben ( Yr6 ) expressed against the race 109E9 of Puccinia striiformis which possesses virulence for Yr6 and avirulence for Yr2 . This supported the hypothesis that Heines Kolben carries the gene Yr2 in addition to Yr6 for resistance to yellow rust in a genetic background in which Yr2 is weakly expressed in seedlings. F1, F2 and F3 progenies from the cross Heines Kolben × Peragis confirmed the monogenic segregation of Yr2 in Heines Kolben and demonstrated the variation of its expression with environmental conditions.