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Focal hepatic and splenic lesions, vascular abnormalities, and disorders of the biliary system can readily be detected with ultrasonography. The sonographic appearance in certain cases may be nonspecific, but the differential diagnosis can be substantially narrowed when the presenting clinical signs are considered. Ultrasonography is less helpful when the liver or spleen is diffusely involved without parenchymal abnormalities. However, certain diseases may also be eliminated from diagnostic consideration on the basis of this finding. Percutaneous ultrasound guided biopsy markedly improves the success and safety of obtaining a definitive diagnosis when either diffuse or focal lesions are present. Sonography has also been very beneficial for serially evaluating the response to therapy once focal lesions of the liver or spleen have been identified.  相似文献   
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Steroid receptors bind to site-specific response elements in chromatin and modulate gene expression in a hormone-dependent fashion. With the use of a tandem array of mouse mammary tumor virus reporter elements and a form of glucocorticoid receptor labeled with green fluorescent protein, targeting of the receptor to response elements in live mouse cells was observed. Photobleaching experiments provide direct evidence that the hormone-occupied receptor undergoes rapid exchange between chromatin and the nucleoplasmic compartment. Thus, the interaction of regulatory proteins with target sites in chromatin is a more dynamic process than previously believed.  相似文献   
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A capture operation to ascertain health status in free-ranging buffaloes from six different areas in the Caprivi Strip in the northeast corner of Namibia was conducted in October 2009. Basic information on the ticks and tick-borne pathogens normally found in wildlife from this area are scarce. The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for ixodid ticks and two selected tick-borne pathogens in the Caprivi Strip, a key area bordering Angola, Zambia, Botswana, and Zimbabwe. Four different tick species have been identified among the 233 collected specimens, and, of 95 tested buffaloes, 54 (57%) were positive for Theileria parva, whereas only 3 (3%) showed evidence of being infected with Ehrlichia ruminantium.  相似文献   
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Analysis of total S in tree foliage has become widely accepted as a means of assessing S pollution of forests when air quality data are lacking. An investigation of total S content of mixed needle samples of different age and canopy height from two stands of young Norway spruce with different densities showed that S-content exceeded the maximum natural S-content (i.e. in the absence of SO2-pollution) for spruce. Significantly higher average needle S contents were encountered with decreasing stand density. Changed aerodynamic roughness and physiological status of thinned trees indicated combined action of atmospheric and tree physiological variables on S deposition and uptake in forest ecosystems. A marked increase in S content from 1 yr old to older needles and from the lower to the upper canopy was observed.  相似文献   
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Abdominal ultrasonography was instrumental in the diagnosis of bilateral ovarian adenocarcinoma in a twelve year old female Irish Setter. Severe ascites limited the diagnostic quality of abdominal radiography, but enhanced ultrasonographic images. Ultrasonographically, the ovarian tumors were large, contained multiple anechoic cystic structures, and had irregular margins. The ultrasonographic appearance of ovarian adenocarcinoma has not been previously reported.  相似文献   
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The detection of small amounts of free peritoneal fluid in the canine patient can be a diagnostic dilemma. Ultrasonography and radiography have been advocated to detect intraabdominal fluid not detectable by physical exam. The purpose of this study was to determine the more sensitive method for detecting small amounts of free peritoneal fluid. Ultrasound examinations and radiographs were performed after increments (1 ml/lb body weight) of fluid were injected intraperitoneally. Ultrasonography detected fluid in one animal at 2 ml/lb. AH other animals had fluid detected at 3 ml/lb. With radiographs fluid could be detected with a high degree of accuracy at 4 ml/lb. The lateral view was more accurate than the ventrodorsal view in detecting fluid. The authors concluded that Ultrasonography is more sensitive than radiography and is the method of choice to detect small amounts of free peritoneal fluid.  相似文献   
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All personnel present in the X-ray examination room during equine radiography were monitored using low energy direct reading ionization chambers (pockets dosimeters) worn outside the lead apron at neck level. The individuals' task and dosimeter readings were recorded after each examination. Average doses ranged from 0 to 6 mrad per study. The greatest exposures were associated with radiography of the shoulder and averaged less than 4 mrad. The individual extending the horse's limb was at greatest risk although the individual holding the horse's halter and the one making the X-ray exposure received similar exposures.
A survey of the overhead tube assembly used for some of the X-ray examinations also was performed. Meter readings obtained indicated an asymetric dose distribution around the tube assembly, with the highest dose occurring on the side to which the exposure cord was attached.
Although the exposures observed were within acceptable limits for occupational workers, we have altered our protocol and no longer radiograph the equine shoulder unless the horse is anesthetized. Continued use of the pocket dosimeters and maintenance of a case record of radiation exposure appears to make the technologists more aware of radiation hazards.  相似文献   
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