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91.
Effects of Escherichia coli heat-stable enterotoxin b on small intestinal villi in pigs, rabbits, and lambs 总被引:4,自引:0,他引:4
Culture supernates from two strains of E. coli were placed into different ligated intestinal sections (loops) of each animal. The two bacterial strains were identical except that one contained a plasmid carrying the heat-stable toxin b (STb) gene, while the other did not. Morphometric techniques were used to assess villous epithelial surface areas and mucosal volumes in both intestinal segments exposed to STb-positive (test) and to STb-negative (control) supernates. In pigs whose intestines were exposed to STb-positive supernatants for 2 hours, both villous epithelial surface area and mucosal volume were significantly smaller in test loops than in control loops (P less than 0.02). In test loops of pigs incubated for 1 hour, and in test loops of lambs incubated for 2 hours, there was a decrease in villous epithelial surface area which approached the test for significance but did not meet it (0.05 less than P less than 0.10). Rabbit test loops did not differ from rabbit control loops in either villous epithelial surface area or mucosal volume. Histological examination of the tissues from all three species revealed epithelial changes in porcine and ovine tissues only. In porcine and ovine tissues, epithelium at villous tips was seen to be cuboidal or squamous, or even to be absent. Villi with similarly altered epithelium were seen in control loops, but were seen much more frequently in test loops. These epithelial changes were seen as early as 30 minutes of incubation in pigs. Intestinal tissues from these pigs were examined by transmission electron microscopy, but no difference between test and control tissues was seen.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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In a series of greenhouse bioassays, tree seedling growth and root-tip development were compared among soils from two areas that had been clearcut and site prepared 16 years earlier and adjacent, undisturbed forest. Seedlings grown in soil from logged areas were shorter and had fewer root tips than those grown in undisturbed forest soil; however, effects on seedling weights were not consistent among species or experimental series. Fertilizing with nitrogen eliminated size differences due to soil source. In Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco], the only species tested in sterilized soils, sterilization of logged soils resulted in increased seedling size and root-tip formation, whereas sterilization of unlogged soils had either no or a negative effect. 相似文献
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P L Rose J P Watkins J A Auer 《Journal of the American Veterinary Medical Association》1984,185(7):795-797
A comminuted, mid-diaphyseal femoral fracture was diagnosed radiographically in a 4-month-old Quarter Horse colt. Disruption of the distal blood supply was suspected, as evidenced by coolness and diminished pulses of the distal portion of the limb. The fracture was repaired by compression plating but the foal's condition continued to deteriorate. A femoral arteriogram of the affected limb was obtained. Positive contrast agent was visible only as far as the mid-shaft of the femur. The foal was euthanatized and the postmortem examination revealed a transected popliteal artery accounting for ischemic necrosis of the distal limb. 相似文献
98.
R J Rose 《The Veterinary record》1978,102(23):498-500
The case histories of four horses with osteomyelitis involving the metacarpal and metatarsal bones are reviewed and the surgical treatments discussed. The horses recovered after curettage of all infected tissue and post operative drainage. The role of antibiotics in treatment is considered and reference is made to the acute treatment of deep wounds to avoid osteomyelitis. 相似文献
99.
Harr KE Raskin RE Heard DJ 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2005,34(4):383-388
BACKGROUND: Few studies have been done to evaluate anticoagulants for use with blood samples from birds and reptiles. Heparin currently is the most commonly used anticoagulant in practice, but may adversely affect blood cell staining and quantitation. OBJECTIVE: The purpose of this study was to evaluate the effects of lithium heparin, K3-EDTA, and sodium citrate, with and without the addition of albumin, on hematologic variables in macaw (Ara sp) and python (Python molurus bivittatus) blood samples. METHODS: Blood samples from 10 macaws and 10 Burmese pythons were collected in heparin-coated syringes and placed into tubes containing either lithium heparin, K3-EDTA, or sodium citrate with and without the addition of 0.25 mL of a 22% bovine serum albumin solution. Cell lysis was determined by counting the number of lysed cells/200 WBCs in Wright's-Giemsa-stained blood smears and by qualitative evaluation of pink plasma in microhematocrit tubes. A CBC was done after 3, 12, and 24 hours of storage at 4 degrees C in anticoagulant-containing tubes and results were compared with those obtained at 0 hour for the heparin-coated syringe sample. A biochemical panel also was done at each time point in similarly stored lithium-heparin samples. RESULTS: Hemolysis was significantly increased in citrated samples from both macaws and pythons beginning at 12 hours. At 24 hours, 19 of 30 (63%) macaw samples in all anticoagulants had >100 lysed cells/200 WBCs. There were no significant differences in hematologic values in samples from pythons collected in heparin or EDTA at any time point. No significant differences were found in the number of lysed cells or in other hematologic data in samples with albumin. Glucose concentration decreased and potassium concentration increased significantly over time in heparinized blood samples. CONCLUSIONS: Based on the results of this study, whole blood samples anticoagulated with lithium heparin or EDTA should be evaluated within 12 hours (macaws) or 24 hours (pythons) of collection and stored at 4 degrees C for best results. Citrate should be avoided as it may result in increased cell lysis. The addition of albumin does not prevent cell lysis. 相似文献
100.
The objective of the study was to determine the disinfection efficacy of aerosolizing (cold fogging) Virkon S on survival of Stahpylococcus aureus and Salmonella enterica on different surfaces. Two experiments were conducted in different locations. Salmonella enterica and S. aureus were grown in broth culture and then seeded into pre-marked areas in each location and allowed to dry. Virkon S (1%) was aerosolized into the rooms (approximately 1L of per 30 m(3)). Samples were collected pre- and post-fogging for quantitative cultures to evaluate the efficacy of aerial disinfection. The reduction of S. enterica or S. aureus counts ranged from 3.40 to 0.95 log(10) (Salmonella) or 4.92 to 0.02 log(10) (Staphylococcus). The greatest reduction was evident in samples collected from non-porous horizontal surfaces, which were not obstructed from the air flow. These results indicate that fogging with Virkon S could be beneficial in routine disinfection of pre-cleaned surfaces. The benefits of routine use of cold fogging with Virkon S in veterinary hospital settings would include its wide-range antimicrobial action and minimal working-men power required to disinfect large areas. Also, fogging would potentially minimize microbial contamination in the hard to reach areas. 相似文献