Serological survey of Toxoplasma gondii,feline immunodeficiency virus and feline leukaemia virus in urban stray cats in Belgium

Three hundred and forty-six serum samples taken between 1998 and 2000 from urban stray cats in the city of Ghent were tested for antibodies to Toxoplasma gondii and feline immunodeficiency virus (FIV), and antigens of feline leukemia virus (FeLV). Of these 346 samples, 243 (70.2 per cent) were seropositive for Tgondii. Thirty-nine cats (11.3 per cent) had antibodies against FIV and 13 (3.8 per cent) had circulating antigens of FeLV. Fewer of the female cats had FIV and heavier cats had a higher seroprevalence of FIV. Exact logistic regression showed that cats that were infected with FIV were more likely to be infected with T gondii (P = 0.04), and the cats with FIV had a higher titre of Tgondii antibodies than FIV-negative animals. However, FeLV was not associated with either T gondii or FIV.     

Preliminary studies on the vascular anatomy of the equine superficial digital flexor tendon.

The vascular and microvascular anatomy of normal equine superficial digital flexor tendons was studied by dissection of vinyl-perfused specimens and by microangiography on high detail film. The presence of an extensive intratendinous vascular latticework was confirmed, and a 'nutrient artery' described closely associated with the accessory ligament of the superficial digital flexor tendon (proximal check ligament). Circumferential stripping of the paratenon from the tendon to eliminate afferent vessels was performed bilaterally in three horses and unilaterally in a fourth, followed by a treadmill training regimen. No resulting intratendinous lesions could be documented on gross post mortem and histological examination at three, 10, or 35 days post operatively. There was mild paratendinous proliferation in all instances. In one horse, four intratendinous ligatures were placed within the medial and lateral borders of the contralateral tendon to isolate further from its blood supply a 10 cm segment. Gross lesions at 35 days post operatively included a marked paratendinous response involving the entire 10 cm segment, and a darkened, soft focus within the core of the tendon. Histopathology and electron microscopy demonstrated focal degeneration. It was concluded that the blood supply of the normal equine superficial digital flexor tendon is primarily intratendinous, rather than paratendinous as previously thought. The lesions in one horse similar to those in naturally occurring tendinitis supported a vascular aetiology of the disease, and set the groundwork for studies aimed at the development of a clinically relevant tendinitis model.     

Myeloperoxidase concentration in bronchoalveolar lavage fluid from healthy horses and those with recurrent airway obstruction

The aim of this work was to measure the myeloperoxidase (MPO) concentration in bronchoalveolar lavage (BAL) fluid collected from horses with recurrent airway obstruction (RAO), both in crisis and in remission, as well as from healthy horses. Seven horses with RAO were exposed to moldy hay until the maximum change in pleural pressure was greater than 1.5 kPa. At that point, BAL was performed, and the total cell counts and percentages in the fluid were immediately determined. To measure the MPO concentration in BAL-fluid supernatant, we used a specific enzyme-linked immunosorbent assay with polyclonal antibodies against equine MPO. The tests were repeated on the horses with RAO after they had spent 2 mo on pasture. Six healthy horses serving as controls underwent the same tests. The absolute and relative neutrophil counts and the MPO concentration in the BAL fluid were significantly greater in the horses with an RAO crisis than in the control horses. After 2 mo on pasture, the horses that had been in RAO crisis were clinically normal, and their neutrophil counts and MPO levels in BAL fluid had significantly decreased; during remission their neutrophil counts were not significantly different from those in the healthy horses, but their MPO concentration remained significantly higher. This study showed that determining the MPO concentration in a horse's BAL fluid is technically possible and that during remission from RAO the concentration remains higher than normal. Thus, MPO may be a marker of neutrophil presence and activation in the lower airways.     

Two cases of atypical mycobacteriosis caused by Mycobacterium szulgai associated with mortality in captive African elephants (Loxodonta africana).

Mycobacterium szulgai was associated with mortality in two captive African elephants (Loxodonta africana) housed at Lincoln Park Zoo. The first elephant presented with severe, acute lameness of the left rear limb. Despite extensive treatments, the animal collapsed and died 13 mo after initial presentation. Necropsy revealed osteomyelitis with loss of the femoral head and acetabulum and pulmonary granulomas with intralesional M. szulgai. The second elephant collapsed during transport to another institution with no premonitory clinical signs. This animal was euthanized because of prolonged recumbency. Granulomatous pneumonia with intralesional M. szulgai was found at necropsy. Two novel immunoassays performed on banked serum samples detected antibody responses to mycobacterial antigens in both infected elephants. It was not possible to determine when the infection was established or how the elephants were infected. When reviewing the epidemiology of this organism in humans, however, transmission between elephants seemed unlikely because human-to-human transmission of this organism has never been reported and a third elephant in the herd was not affected. In addition to Mycobacterium bovis and Mycobacterium tuberculosis, atypical mycobacterial organisms need to be considered potentially pathogenic in elephants.     

Characterization of Growth, Nitrogen Accumulation and Competitive Ability of Six Tropical Legumes for Potential Use in Intercropping Systems

Legume cover crops can be successfully used as intercrop or relay crops in low-input farming systems. To select appropriate species for intercropping, experiments were conducted in the savannah zone of Côte d'Ivoire during the wet seasons of 1997 and 1998 to determine the growth and nitrogen (N) accumulation of six cover legumes as well as the characteristics indicative of competitive ability. The species included the erect growing Crotalaria juncea and Cajanus cajan , the creeping species Mucuna pruriens var. cochinchinensis and Calopogonium mucunoides and the bushy herbaceous species Aeschynomene histrix and Stylosanthes hamata . Marked differences in phenology were observed as S. hamata and C. juncea flowered around 45–55 days after sowing (DAS) and the other species around 80–95 DAS. C. juncea and C. cajan produced close to 9 ton dry matter ha^–1, whereas the other species produced less than half this amount. The average estimated amount of accumulated N, based on leaf material, was around 70 kg ha^–1 for all species except S. hamata and A. histrix , which only produced around 25 kg ha^–1. Based on morphological characteristics, C. juncea , C. cajan and the short-lived M. pruriens were identified as potentially most competitive, indicating that productivity and competitive ability are strongly linked. The implications of these findings for intercropping systems in upland rice production are discussed.