Liver biopsy techniques for adult horses and neonatal foals to assess copper status

Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares.     

Attenuation of low-frequency sound in freshwater

Lake Superior was chosen as an experimental site to compare sound absorption of freshwater with the results of absorption measurements in seawater. The relaxation-like absorption at 1 kilohertz occurring in seawater is also present in freshwater. A relaxation related to the structural characteristics rather than to the salt content of water may be responsible for the anomalous absorption.     

Embedded nanostructures revealed in three dimensions

Nanotechnology creates a new challenge for materials characterization because device properties now depend on size and shape as much as they depend on the traditional parameters of structure and composition. Here we show that Z-contrast tomography in the scanning transmission electron microscope has been developed to determine the complete three-dimensional size and shape of embedded structures with a resolution of approximately 1 cubic nanometer. The results from a tin/silicon quantum dot system show that the positions of the quantum dots and their size, shape, structure, and formation mechanism can be determined directly. These methods are applicable to any system, providing a unique and versatile three-dimensional visualization tool.     

Detomidine-butorphanol sedation in equine clinical practice

Combinations of detomidine (mean dose rate 13 micrograms/kg) and butorphanol (mean dose rate 26 micrograms/kg) were used to sedate 61 horses for a variety of surgical or diagnostic procedures in general equine practice. Three horses were sedated on more than one occasion. The degree of sedation was graded from 3 to 0 (deep sedation to no effect) and any side effects were recorded. Forty-three per cent of the horses were graded 3, 46 per cent were graded 2, 8 per cent were graded 1 and 3 per cent were graded 0. Bradycardia and ataxia were the major side effects. The combination was judged to be effective and safe for use in general practice. In 56 horses (92 per cent) the necessary procedure was carried out under excellent conditions and in only one horse was the degree of sedation considered to be totally unsatisfactory.