Thoracic radiographic features of silicosis in 19 horses.

Clinical records and thoracic radiographs of 19 horses with a confirmed pathologic diagnosis of silicosis were reviewed. These horses had histories of varying degrees of chronic weight loss, exercise intolerance, and respiratory distress. At the time of presentation, two horses were asymptomatic. Ten horses were geldings and nine were female. The mean age of the 19 horses was 10.7 +/- 5.5 years. Fourteen horses were identified as being from the Monterey-Carmel Peninsula of midcoastal California. An abnormal, structured interstitial pulmonary pattern was identified on thoracic radiographs in each horse. The interstitial pulmonary changes were classified as miliary (13 horses), reticulonodular (4), or linear interstitial (2), and were best visualized dorsally and caudodorsally. In addition to the abnormal interstitial pulmonary pattern, areas of pulmonary consolidation were evident caudodorsally in seven horses. Other thoracic radiographic features included: hilar lymphadenopathy (4 horses), pleural effusion/thickening (4), cranial mediastinal lymphadenopathy (2), hyperinflation (1), and a discrete pulmonary mass (1). Necropsy findings in eight horses and results of lung biopsies in an additional five horses showed a diffuse, multifocal, granulomatous pneumonia with areas of pulmonary fibrosis. Cellular infiltrates included predominantly macrophages with intracellular and/or extracellular crystalline material, occasional lymphocytes, and giant cells. Similar cellular changes were also identified, during necropsy, in the hilar and tracheobronchial lymph nodes in each of the eight horses, although gross enlargement of the lymph nodes was present in only six horses. The radiographic and pathologic findings of these 19 horses are consistent with chronic or the accelerated forms of silicosis that are recognized in humans.

Comparison of two sample collection methods for quantitative bacteriologic culture of canine prostatic fluid.

Ejaculate, urine, urethral swab specimens, and ultrasonography-guided small-needle prostatic cyst aspiration and/or tissue core biopsy specimens were collected for bacteriologic culture from 25 dogs in which prostatic disease was suspected on the basis of history, clinical signs of disease, or results of physical examination. The prostate gland in each dog was examined ultrasonographically, and the tissue core biopsy specimens were examined histologically and bacteriologically. Two methods were used to assess bacterial prostatitis. In 5 dogs (20%), bacteriologic culture results of paired urethral swab and ejaculate specimens differed from culture results of specimens obtained by needle aspiration of prostatic cyst fluid or tissue core biopsy. The prostate gland in 17 dogs had 1 or more cystic, fluid-filled structures (0.5 to 4.0 cm in diameter). Ultrasonographic appearance of the prostate gland did not have obvious correlation with culture results from dogs of the study. Histologic results of prostatic tissue core biopsy specimens correlated well with culture results.

Sonography of the liver, gallbladder, and spleen.

Focal hepatic and splenic lesions, vascular abnormalities, and disorders of the biliary system can readily be detected with ultrasonography. The sonographic 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.

Gadolinium-DTPA enhancement of VX-2 carcinoma of the rabbit kidney on T1 weighted magnetic resonance images.

Experimental renal carcinoma was induced by percutaneous injection of VX-2 carcinoma cells into the left kidney in New Zealand white rabbits. Magnetic resonance imaging (MRI) was performed at 0.15 T before and after intravenous injection of 0.3 mmol gadolinium-DTPA (Gd-DTPA) per kg body weight. Gd-DTPA enhanced the tumors by increasing the signal intensity on T1 weighted images. The enhancement was evident immediately after Gd-DTPA injection, increasing during the observation time of 30 minutes. Histologically the areas of enhancement corresponded well to the viable tumor tissue.

Gadolinium-DTPA enhancement of experimental soft tissue carcinoma and hemorrhage in magnetic resonance imaging.

An experimental series in the rabbit was performed to test gadolinium-DTPA (Gd-DTPA) enhancement of VX-2 carcinoma and hemorrhages induced in the soft tissues. The recognition of both malignant and benign lesions was greatly facilitated on T1 weighted images after intravenous administration of 0.3 mmol Gd-DTPA/kg body weight because of reduced T1 relaxation times. Gd-DTPA enhancement reached its maximum after 10-15 minutes and was most apparent in tumor tissue, connective tissue surrounding the tumor and in the area of fresh hemorrhage.

Ectopic ureter in a dog: extension from the kidney to the urinary bladder and to the urethra.

An ectopic ureter extending to the urinary bladder and to the proximal portion of the urethra was diagnosed in a 6-month-old dog with urinary incontinence. The diagnosis was made by use of excretory urography. The kidney and ureter were removed. When urinary incontinence continued, positive-contrast cystography was performed. The ectopic ureter was found to bypass the bladder via a submucosal extension that emptied into the urethra.

Sonography of the liver, gallbladder, and spleen.

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.

Purification and characterization of wheat germ DNA topoisomerase I (nicking-closing enzyme).

Wheat germ contains an enzyme capable of removing supercoils from circular DNA. We have purified this enzyme using Polymin P fractionation, ammonium sulfate precipitation, and chromatography on Bio-Rex 70 and phenyl-Sepharose. Renaturation after electrophoresis on sodium dodecyl sulfate-polyacrylamide gels shows that topoisomerase activity is associated with a polypeptide with a Mr = about 111,000. The enzyme is similar to other eukaryotic type I DNA topoisomerases (nicking-closing enzymes) by the following criteria: it is capable of increasing or decreasing the topological linking number of covalently closed DNA substrate; it is capable of restoring an equilibrium distribution of linking numbers to DNA substrate with a single unique linking number; and it does not require magnesium ion or ATP for activity.