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51.
Distribution patterns of calcium in peat deposits of seventeen bogs in the middle and southern taiga of Western Siberia have been studied. Four types of Ca distribution patterns related to the genesis of peat deposits are specified. Up to three Ca-enriched peat layers are distinguished in thick deposits. This Ca distribution pattern is typical of different peat deposits formed under various conditions. It is shown that Ca accumulation in particular layers of peat deposits is related to the warm stages of the Holocene.  相似文献   
52.
A ten-year-old female poodle was presented for left hindlimb lameness. Radiographically, irregular intramedullary densities of long bones (bone infarcts) and a lytic lesion in the left distal femur were detected. Two years after the first examination, the lesions in the distal femur were definitely identified as osteosarcoma and the dog was euthanized. Pathological and histological changes of the bone infarcts as well as of the osteosarcoma are described. Regarding bibliographical data, occurrence and aetiopathogenesis of osteosarcoma associated with multifocal bone infarction in man and dog are discussed.  相似文献   
53.
The severe fibrinonecrotic pneumonia associated with pneumonic pasteurellosis usually results from colonization of the lower respiratory tract by Pasteurella haemolytica biotype A, serotype 1(A1). Despite recent research efforts, the authors lack a detailed understanding of the interactions and host response to P. haemolytica in the respiratory tract. The authors hypothesize that management and environmental stress factors or viral infection alters the upper respiratory tract (URT) epithelium allowing P. haemolytica to colonize the epithelium. Once the URT is colonized, large numbers of organisms enter the lung where they interact with alveolar macrophages. Endotoxin, released from the bacteria, crosses the alveolar wall where it activates pulmonary intravascular macrophages, endothelium, neutrophils, lymphocytes, platelets, complement, and Hageman factor leading to complex interactions of cells and mediators. It is the progression of this inflammatory response with neutrophil influx that is ultimately responsible for the pulmonary injury. Leukotoxin is a major virulence factor of P. haemolytica that allows it to survive by destroying phagocytic cells. At subcytolytic concentrations it may also enhance the inflammatory response by activating cells to produce mediators and release reactive oxygen metabolites and proteases.  相似文献   
54.
Spleen cells from Toxoplasma lysate antigen (TLA)-sensitized BALB/c mice showed the strong cytotoxic activity against both natural killer (NK)-sensitive cells (YAC-1 and RL male-1) and NK-insensitive cells (P-815), when incubated with TLA or recombinant human IL-2 (rhIL-2). The increment of TLA concentration in culture medium increased the cytotoxic activity. Treatment of effector cells; spleen cells from TLA-sensitized mice incubated with TLA, with anti-asialo GM1 or anti-Thy-1 plus complement inhibited the cytotoxic activity of effector cells, whereas treatment with anti-mouse Lyt-2.2 serum plus complement had no effect on the cytotoxic activity. Treatment of spleen cells from TLA-sensitized mice with anti-asialo GM1 and/or anti-Thy-1 plus complement inhibited cytotoxic activities of effector cells. These results suggested that spleen cells sensitized with TLA both in vivo and in vitro were asialo GM1 positive and Thy-1 positive, and the majority of cytotoxic cells induced by TLA were similar to lymphokine-activated killer (LAK) cells induced by IL-2.  相似文献   
55.
The prevalence of bovine respiratory disease (BRD) was assessed in a population of 10,142 beef calves representing nine pure breeds and three composite populations born in 1983 through 1988. Twenty-four percent of the calves experienced at least one episode of respiratory disease during the 1st yr of life; frequencies over the six birth years ranged from 14 to 38%. The timing of respiratory disease outbreaks differed among birth years; in 4 of the 6 yr, more illness occurred in the pasture before weaning than in the feedlot after weaning. Frequencies of BRD during preweaning and postweaning periods were analyzed separately. Pure breeds and composite populations within a single preweaning location differed in frequency of illness during the preweaning period. However, not all possible breed comparisons could be made because preweaning location differed for the breed groups, and preweaning location had a significant effect on the frequency of respiratory disease in the preweaning period. The preweaning location effect did not carry through to the postweaning period. Pinzgauers had the highest BRD frequency within the feedlot (24.6%). The heritability estimates of BRD during the preweaning and postweaning periods did not differ significantly from 0 (.10 +/- .02 and .06 +/- .07, respectively). Although it is likely that response to selection for resistance to BRD would be slight using the animal's history of BRD as the selection criterion, including information on relatives or additional immune traits may improve the accuracy of an estimated breeding value for BRD resistance.  相似文献   
56.
Two mungbean varieties, Guj-1 and PIMS-1 differing in their productivity potential, were examined to investigate their photosynthetic system at various stages of growth in relation to yield with two different dates of sowing. Vertical leaves were found to be beneficial. On the other hand, excessive leaf area during the later stages of growth may be detrimental to yield. Lower LAD at seedling stage and overall high NAR values may be reflected in higher grain yield. NAR declined as season progressed and this, in turn, may be related with increase in LAI. The grain yield was considerably more at the first date of sowing as compared to second date of sowing, the effect was being more pronounced in var. PIMS-1 . Various environmental factors recorded at two different dates of sowing and at various stages of growth indicated that these factors may have influenced the yield potential at two different dates of sowing.  相似文献   
57.
Interrelations between host, bacterium and antibiotic compound in antibiotic therapy of bacterial infections are analysed. Some methods for the evaluation of antibacterial activity of antibiotics in vitro are described and their limits, in particular of the widely used MIC tests, are demonstrated. Data from trials comparing antibiotic applications once and twice a day as well as discussions in chemotherapy, concerning the applicability of in vitro results to therapy, are used to try to find practicable guidelines for the repetition of antibiotic therapy.  相似文献   
58.
With the help of a new synthetic material follicles and corpora lutea from the ovaries of 80 cows in different stages of the sexual cycle were examined for modifications of their blood vessel architecture. In the theca externa the main artery which runs towards the follicle, separates into arterioles of which capillaries derive in the theca interna, building a basket-like network around the zona granulosa. After ovulation the follicle wall forms characteristic fields. Capillaries grow into the zona granulosa and thus the folds form the lobular structure of the corpus luteum. Capillaries which rise from the ruptured part of the follicle, spread centripetally and together with lutein cells they build up the not lobulated cupola of the corpus luteum. The regression of the corpus luteum starts around the 16th day of the cycle, beginning at the capillary network of the cupola. A contraction of the vessels and a quick decrease of the volume follow.  相似文献   
59.
Squamous cell carcinoma is an uncommon tumor of the cornea in dogs. A 12-year-old Shih Tzu with a history of chronic keratoconjunctivitis sicca was diagnosed as having squamous cell carcinoma of the corneoscleral limbus. The lesion was treated by surgical resection and cryotherapy. One year after surgery, multiple tumors, apparently unrelated to the first tumor, appeared on the same cornea. Keratoconjunctivitis sicca may have predisposed the dog to corneal squamous cell carcinoma development.  相似文献   
60.
Twenty-nine pruritic, atopic dogs were entered into a double-blind, placebo-controlled, crossover study to evaluate the efficacy of an investigational antiallergenic compound, AHR-13268. Fourteen dogs were evaluated by a veterinary dermatologist (at intervals) and the owner (daily). Fifteen dogs were evaluated only by the owner. The mean (+/- SE) owner scores for pruritus, erythema, and lesions with placebo treatment (higher score = worse signs) were 3.24 (+/- 0.12), 2.73 (+/- 0.12), and 2.61 (+/- 0.09), respectively. With drug treatment, the corresponding scores were 2.89 (+/- 0.12), 2.50 (+/- 0.12), and 2.25 (+/- 0.09). Scores for pruritus and lesions (but not erythema) were significantly better with drug treatment than with placebo treatment. Investigator scores showed similar trends, but the differences were not great enough to be statistically significant. Overall, 11/29 (38%) owners reported their dogs had moderate or better improvement from drug capsules, and 4/29 dogs (14%) improved on placebo capsules. A variety of adverse effects were reported following both drug (9/29 dogs) and placebo (8/29 dogs) capsule administration, but were mild and well tolerated. Results of this study indicate that AHR-13268 has potential for empiric treatment of allergic inhalant dermatitis in some dogs.  相似文献   
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