An immune-complex glomerulonephritis of Chinook salmon, Oncorhynchus tshawytscha (Walbaum)

Chinook salmon from New Zealand were shown to have a generalized membranous glomerulonephritis that was most severe in large fish. Marked thickening of the glomerular basement membrane was the most consistent lesion, with the presence of an electron-dense deposit beneath the capillary endothelium.Severely affected glomeruli also had expansion of the mesangium and loss of capillaries,synechiae of the visceral and parietal epithelium and mild fibrosis of Bowmans capsule. Chinook salmon from British Columbia, Canada with bacterial kidney disease caused by Renibacterium salmoninarum had similar histological lesions. They also had thickened glomerular basement membranes that were recognized by rabbit antiserum to rainbow trout immunoglobulin. This was true only when frozen sections of kidney were used and not formalin-fixed tissue. An attempt to experimentally produce a glomerulopathy in rainbow trout by repeated immunization with killed R. salmoninarum was not successful. Case records from the Fish Pathology Laboratory at the University of Guelph over a 10-year period revealed that a range of species were diagnosed with glomerulopathies similar to those seen in Chinook salmon. The majority of these cases were determined to have chronic inflammatory disease. This report has identified the presence of immunoglobulin within thickened basement membranes of Chinook salmon with glomerulonephritis and supports the existence of type III hypersensitivity in fish.     

Neutrophil function in sheep experimentally infected with bovine leukemia virus

In vitro neutrophil adherence, random migration, chemotaxis, resting and phagocytosis-associated oxygen consumption and bactericidal responses were assessed in sheep experimentally infected with bovine leukemia virus (BLV). Neutrophil function was examined in two groups of 9 control and 9 BLV-infected sheep at 0, 1, 2, 3, 5, 7, 11 and 15 weeks post-infection. Enhanced neutrophil adherence, chemotaxis and resting oxygen consumption responses were found in the infected group at 2, 11 and 15 weeks respectively. Significant alterations between groups were not demonstrated during the other time intervals.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

冬季日光温室的保温措施及对天气性灾害的预防对策

高效节能日光温室以太阳能为主要能源 ,不加温或临时加温就能进行果菜类生产 ,但近几年发展的温室偏高偏宽 ,保温措施又跟不上 ,结果在1 999年冬至 2 0 0 0年春雪多、严寒的条件下 ,不少温室出现了 2℃以下低温 ,甚至冻害 ,使果菜类生产受到很大影响 ,造成了很大的损失。对此 ,我站经过试验和调研 ,提出如下的保温措施及对天气灾害性的对策 ,使果菜类冬季能在日光温室得以正常生长 ,进一步提高冬季蔬菜生产的经济效益和社会效益 ,保证我市保护地蔬菜生产持续发展。1　温室结构与保温的关系沈阳市地处北纬 41°以北 ,冬至太阳高度角低 ,中午 …     

Experimentally induced Faciola hepatica infection in white-tailed deer. I. Clinicopathological and parasitological features.

Six white-tailed deer (Odocoileus virginianus) and six sheep were inoculated with metacercariae of Fasciola hepatica. Two animals of each species were given 100, 500 or 2500 metacercariae. Clinicopathological features of these infections were determined by analyses of blood samples collected each week from inoculated deer and sheep as well as from two noninoculated animals of each species. One animal in each inoculated group was killed and examined at six weeks postinoculation and the remainder at 15 weeks postinoculation. Compared with the values obtained from noninoculated controls, eosinophilia, hyperproteinemia and hyperglobulinemia occured in inoculated deer. There were no other significant changes in hematological values or in serum aspartate aminotransferase levels. Marked leukocytosis and eosinophilia, with hyperproteinemia, hyperglobulinemia, hypoalbuminemia, elevated serum aspartate aminotransferase levels and mild macrocytic normochromic anemia characterized the infection in lambs. Although approximately 29% of the inoculum was recovered from the hepatic parenchyma of the sheep, F. hepatica was found in only one of six inoculated deer. A patent infection was established in this deer and constitutes the second report of mature F. hepatica in this host.     

Hematology and biochemistry reference values for the ranch fox.

Reference hematology and biochemistry values are presented from a mixed population of 30 silver and red foxes of both sexes, reared and living under fox-farming conditions in southern Ontario. Based on history and physical examination, the animals in this study were clinically healthy at the time of blood collection and maintained under similar husbandry practices. The observations were examined for outliers and Gaussian distribution before and after one of three transformations. Parametric analysis was used to determine lower and upper reference limits. Where observations were not Gaussian, minimum and maximum values are given. These reference values are presented as a usable first approximation of population reference values to assist clinicians and researchers in their interpretation of observations obtained from foxes of similar populations.