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81.
James W. Ticer Crispin P. Spencer Norman Ackerman 《Veterinary radiology & ultrasound》1980,21(1):12-17
ansitional cell urethral carcinoma in four female dogs is reported. Lesion distribution in the proximal two thirds of the urethra and the radiographic appearance with retrograde positive contrast urethrography were similar in each dog. The normally smooth longitudinal urethral striations were replaced by multiple small, poorly marginated intraluminal masses that resulted in a generalized moth-eaten appearance. Extension of contrast medium into the periurethral tissues also occurred. Retrograde urethrography, a simple diagnostic technic, aided in establishing a differential diagnosis in dogs that had urine retention and stranguria. 相似文献
82.
Radiographic evaluation of uterine enlargement is discussed and illustrated. Normal (pregnancy) and abnormal (pyometra, complications of pregnancy, neoplasma) causes of uterine enlargement are addressed. Special radiographic procedures for uterine evaluation are described. 相似文献
83.
In evaluating radiographs of the limb joints and head, students encounter difficulty where superimposition occurs. By replacing calcium with silver salts in the bone, enhanced radiopacity can be produced. In this study, silver impregnation was used to increase the radiopacity of individual carpal and tarsal bones, selected bones of the skull and the sinuses, and guttural pouch of the horse. This provides an interpretation aid for teaching radiographic anatomy of these regions. 相似文献
84.
Holland MS Tai MH Trosko JE Griffin LD Stasko JA Cheville NC Holland RE 《American journal of veterinary research》2003,64(4):396-403
OBJECTIVE: To isolate bovine mammary gland cells with stem cell characteristics. SAMPLE POPULATION: Monolayers of bovine mammary gland cells. PROCEDURE: Mammary gland cell populations were separated by use of selected media supplements. Phenotypic characteristics were examined via light and transmission electron microscopy. Cellular expression of casein and connexin 43 was identified immunohistochemically. A scrape-loading and dye transfer assay was used to examine the mammary gland cell populations for homogenous gap junctional intercellular communication (GJIC). RESULTS: Subpopulations of mammary gland cells grown in vitro are classified on the basis of their distinct morphologic features and ability to communicate via gap junctions. Ultrastructurally, 2 morphologically distinct cell types were classified as type I and II cells. Type I cells were small light undiffertiated cells and large light undifferentiated cells that were deficient in functional gap junctions (as is characteristic of stem cells). Type II cells included large light differentiated cells and terminally differentiated cells; GJIC was functional in type II cells. Type II cells had cytoplasmic expression of connexin 43, whereas, type I cells did not. All cells expressed casein. CONCLUSIONS AND CLINICAL RELEVANCE: Subpopulations of bovine mammary gland cells with stem cell characteristics were identified. Phenotypic differences are observed among type I bovine mammary gland cells with stem cell characteristics. Gap junctional intercellular communication may be necessary for the differentiation of stem cells. Characterization of bovine mammary gland stem cells and their progeny may provide a new tool with which to study mammary gland health. 相似文献
85.
Campylobacter jejuni, a foodborne pathogen closely associated with market poultry, is considered to be the most frequent agent of human gastroenteritis in the United States. The pathways involved in the contamination of poultry flocks, vertical transmission and/or horizontal transmission, are unclear. In this study, Campylobacter isolates from two independent commercial broiler breeder flocks, as well as from their respective progeny, were characterized and compared by PstI ribotype analysis and by DNA sequence analysis of the short variable region (SVR) of the flaA gene (flaA SVR). Campylobacter isolates originating from one set of breeder hens and the feces from their respective progeny demonstrated identical ribotype patterns as well as identical flaA SVR DNA sequences, thereby suggesting that these isolates were clonal in origin. Ribotype analysis of Campylobacter isolates from the second set of breeder hens and processed carcasses from their offspring resulted in two patterns. Sequence analysis placed these isolates into two closely related groups and one distant group, similar to the ribotype analysis. These results demonstrate that Campylobacter isolates from commercial broiler breeder flocks and from the respective broiler progeny may be of clonal origin and that breeder hens can serve as a source for Campylobacter contamination in poultry flocks. 相似文献
86.
Associations between age or sex and prevalence of gastric ulceration in Standardbred racehorses in training 总被引:1,自引:0,他引:1
Rabuffo TS Orsini JA Sullivan E Engiles J Norman T Boston R 《Journal of the American Veterinary Medical Association》2002,221(8):1156-1159
OBJECTIVE: To determine associations between age, sex, or medical treatment and prevalence and severity of gastric ulceration in Standardbred racehorses in training. DESIGN: Cross-sectional study. ANIMALS: 224 Standardbred racehorses in training. PROCEDURE: Gastroscopy was performed on each horse, and mucosal ulceration was graded from 0 (normal mucosa, no lesions) to 3 (extensive, often coalescing, lesions with areas of deep ulceration). Associations between age, sex, or treatment and prevalence and severity of ulcers were evaluated. RESULTS: Prevalence of gastric ulceration was 87%. Although there was little association between age and prevalence of ulcers, there was an association between age and severity of ulcers. Most 2-year-old horses (57.7%) had an ulcer score of 0 or 1. In all other age groups, most (58% to 82.61%) of horses had an ulcer score of 2 or 3. Although overall prevalence of ulceration was comparable among sex groups, the relative risk for gastric ulceration increased with age in castrated males, whereas it decreased in females and sexually intact males. CONCLUSIONS AND CLINICAL RELEVANCE: Gastric ulceration is common in Standardbred horses in race training. Severity is higher in horses > or = 3 years of age than in 2-year-old horses. Relative risk for ulceration increases with age in castrated males. 相似文献
87.
88.
89.
In association with industry, an extensive database has been established on measurements of sea louse counts on farmed Atlantic salmon for the years 1996 to 2000 from 33 Scottish fish farms. These data include extensive counts on the sea louse species, Lepeophtheirus salmonis, at various stages of the life cycle and in particular the chalimus and mobile stages. There has been considerable speculation as to what factors might affect the abundance of sea lice, much of which is based on limited evidence. Our analyses show that there is tremendous variation in sea louse infestation patterns from year to year, whereas stock type, geographical region and coastal exposure do not appear to affect mean levels of abundance. In contrast, treatments lead to pronounced cycles of sea louse infestation with peaks and troughs at 3-week intervals, and these interventions are important if the sea louse levels on fish are to be controlled. There was no evidence of water temperature affecting the mean annual abundance of sea louse infestation. 相似文献
90.
Empirical relationships between land use/cover and estuarine condition in the Northeastern United States 总被引:1,自引:0,他引:1
Wilfrid Rodriguez Peter V. August Yeqiao Wang John F. Paul Arthur Gold Norman Rubinstein 《Landscape Ecology》2007,22(3):403-417
Land–water interactions were examined in three regions in the Virginian Biogeographic Province; the southern shore of Cape
Cod, Massachusetts; the Hudson/Raritan region of New York; and the eastern shore of the Delmarva (Delaware/Maryland/Virginia)
Peninsula. Cumulative distribution functions were used to evaluate similarity in environmental condition among estuaries.
Spatial-setting variables (location in a river, coastal lagoon, or in open waters) were associated with variation for some
measures of estuarine condition. Patterns of coastal urban and agriculture gradients were measured and their relationship
with indicators of estuarine condition was modeled statistically. When estuaries were pooled, the highest variation explained
by spatial-setting variables was found for dissolved oxygen (DO, R
2 = 0.44) and salinity (R
2 = 0.58), with DO decreasing in river locations and salinity decreasing with rainfall and sampling locations near rivers.
The explanatory power for the other indicator variables was low and varied from 6% to 27%. Rainfall explained some of the
variation (R
2 = 0.23) in total suspended solids. Moderate (0.4 < | r | < 0.7) to strong (| r | ≥ 0.7) linear associations were found between total urban area and measures of estuarine condition. Within regions, total
urban area was positively associated with Silver (r = 0.59), Cadmium (r = 0.65), and Mercury (r = 0.47) in Cape Cod, and inversely related to DO (r = −0.65) in the Hudson/Raritan region. No associations were found in the Delmarva Peninsula study area. Total area of agriculture
showed a moderate association with Arsenic in Cape Cod, but no other associations were found in the other two regions. Our
analyses show a measurable impact of urban land use on coastal ecosystem condition over large areas of the northeastern United
States. This pattern was most evident when many different landscapes were considered simultaneously. The relationship between
urban development and estuarine condition were weaker within the individual regions studied. The use of land use/cover models
for predicting estuarine condition is a challenging task that warrants enhancements in the type, quantity, and quality of
data to improve our ability to discern relationships between anthropogenic activities on land and the condition of coastal
environments. 相似文献