The morphological changes in the region of the reticulum were examined ultrasonographically in 26 cows with traumatic reticuloperitonitis, and a radiograph of the reticulum was also taken. The ultrasonographic examination included observations of reticular motility during a three minute period, of reticular contours and of adjacent structures such as the diaphragm, the anterior dorsal blind sac of the rumen, the ventral sac of the rumen, the spleen, omasum, abomasum and liver. In cows with disturbed reticular motility, biphasic contractions were slower than normal or indistinct, and the number of contractions was reduced. Fibrinous changes appeared as echogenic deposits, sometimes accompanied by hypoechogenic fluid. Abscesses had an echogenic capsule with a hypoechogenic centre. In seven cows, there was an effusion in the region of the reticulum in addition to the morphological changes. The spleen was involved in the adhesions in four cows, the omasum in three cows, the liver in one cow and the abomasum in one cow. Radiography revealed foreign bodies penetrating the reticulum of 12 cows and magnets in the reticulum of seven cows. None of these foreign bodies or magnets could be visualised by ultrasonography.

Low bone mass as estimated by decreased bone mineral density (BMD) is an established predictor of osteoporotic fractures. One of the latest developments in bone densitometry is peripheral quantitative computed tomography (pQCT) of the forearm. In Germany, the CT bone scanner XCT 900 has already been widely used; however, interpretation of measurements with respect to osteoporosis risk assessment can be improved by better defined and validated reference data. In the present study, this device was used to measure BMD at the distal radius in a well-defined healthy population of 179 German adults (91 men, 88 women) aged 20-79 years. In vivo precision was 1.67% for trabecular and 0.81% for total BMD measurements. Peak values of trabecular and total BMD were observed at the ages 40-50 years in women and 30-40 years in men. Beyond these ages, both trabecular and total BMD showed a linear decline with age, decreasing by 0.85% and 1.08% per year in women and by 0.59% and 0.54% in men, respectively. Measures of BMD were not influenced by weight, height or body mass index (BMI). In both sexes, trabecular and total radial BMD showed a positive and significant correlation with femoral BMD measures obtained by dual X-ray absorptiometry (DXA). Weaker correlations were observed with DXA measures of the lumbar spine. Compared with the 95% reference range provided by the manufacturer, the distribution of age- and sex-specific values of trabecular BMD of the distal radius was shifted to lower values by up to 1 standard deviation.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonthermal in vitro ablation of bovine neural tissue by using laser-induced optical breakdown generated by ultrashort laser pulses, with durations from 100 fs to 35 ps and pulse energies of up to 165 µJ, has been investigated. The experiments were performed at wavelengths ranging from 630 to 1053 nm by using a femtosecond Ti:Sapphire laser, a femtosecond dye laser, and a picosecond Nd:YLF laser system. Tissue ablations have been achieved by focusing the laser beam on the surface of the tissue, to a spot diameter of 5-20 µm, resulting in the generation of a microplasma. Laser pulses from the Ti:Sapphire laser with 140 fs duration showed a two times higher efficiency of ablation than the longer 30 ps pulses from a Nd:YLF laser with an identical pulse energy. At pulse energies of 140 µJ, single pass excisions deeper than 200 µm were generated by the 140 fs pulses. In addition, the fluence at threshold of the ablation was found to be reduced for shorter pulse durations. For 3 ps laser pulses at 630 nm, we measured the fluence at threshold to be about 5.3 J/cm 2 ; for 100 fs pulses from the same laser the experimental threshold was at 1.5 J/cm 2. Histopathological examinations and scanning electron micrographs confirm the high quality of the excisions. No sign of significant thermal damage was observed.

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The radiographic and ultrasonographic findings in 26 cows with traumatic reticuloperitonitis were compared. The cows were divided into three groups based on the radiographic findings; the first group consisted of 12 cows in which the principal radiographic finding was a foreign body penetrating the reticulum; the second group contained four cows in which the principal radiographic finding was gas shadows or a gas-fluid interface, the third group consisted of 10 cows that had no reliable radiographic evidence of traumatic reticuloperitonitis, such as an abnormal contour, position or shape of the reticulum. In no case could the foreign bodies be visualised by ultrasonography. In all the cows except one with radiographic evidence of abnormal gas inclusions and gas-fluid interfaces, ultrasonography revealed echogenic, partitioned and capsulated structures with central hypoechogenic cavities. In addition, in some of the cows with no radiographic evidence of the condition, severe changes indicative of inflammatory processes were visible by ultrasonography.