Permanent ligation of arteries supplying blood to the spinal cord in operations for aortic aneurysm can lead to spinal cord ischemia, which can result in either paraparesis or paraplegia. This report describes a rapid method of intraoperative identification of those arteries that supply the spinal cord by use of an intrathecal platinum electrode to detect hydrogen in solution that has been injected into the aortic ostia. Preservation or perfusion of those identified arteries supplying the spinal cord may decrease the rate of postoperative neurologic complications. Of 28 porcine experiments with postoperative observation for 24 hours, there were 3 initial pilot experiments in which saline saturated with hydrogen was injected into the temporarily cross-clamped aorta. Twenty animals were then randomized to (1) preservation of only the vessels sequentially identified to supply blood to the spinal cord from T-13 to L-5 (n = 10); (2) division of the vessels supplying the spinal cord (n = 10). A further five animals underwent perfusion experiments wherein the identified cord arteries were perfused by a shunt, the other nonsupply arteries were divided, and the aorta was kept clamped for 45 minutes. Spinal motor evoked potentials were elicited with an intrathecal electrode and were highly sensitive for paralysis. Paralysis occurred in 0/3 pilot (p less than 0.013 vs division); 8/10 division; 1/10 preservation (p less than 0.0017 vs division); and perfusion 1/5 (p less than 0.025 vs division). Results of a pilot study in eight humans shows that the technique can be used to rapidly identify segmental arteries supplying the spinal cord, to determine if distal perfusion is supplying the spinal cord with blood flow, and if reattached segmental arteries are patent.

sented. It is found that the SAW streaming depends on the SAW power, frequency, pulse Various liquid motions such as width, the liquid volume and surface chemstreaming and droplet formation have been ical conditions of the substrate surface. observed when a liquid was put on the If the surface is hydrophobic, liquid surface of SAW propagation substrate. In droplets are effectively ejected from the this report we call these phenomena "SAW surface into the air at an oblique angle. streaming" and experimental and theoreti-Under the proper condition, very fine fogs cal studies are presented. Surface treat-are produced. ment of SAW substrate by metalization and Theoretically, a general differential by silanization is employed to demonstrate equation of second order which is used for that the liquid motion is strongly influ-the acoustic streaming theory3) is develenced by the chemical condition of the oped. It is shown that the calculated substrate surface. Experiments using 128' force of SAW streaming due to leaky rot. Y-X LiNb03 at the frequency of 50 MHz Rayleigh wave is much greater than that of with various pulse width are described.acoustic streaming due to general attenu-Theoretically, SAW streaming force ated plane traveling waves in bulk liquid. can be derived using the acoustic streaming theory. The calculated SAW streaming force is found to be very large and strong enough to expel the droplet from the liquid surface.0090-5607/89/0000-0643 $1 .OO 0 1989 IEEE

Various liquid motions such as streaming and droplet formation on the surface of SAW propagation substrate are called SAW streaming. Experiments on SAW streaming using 128° rot. Y–X LiNbO3 at the frequency of 50 MHz with various pulse widths are described. Surface treatment of SAW substrate by silanization is employed to demonstrate the droplet ejection. Theoretically, SAW streaming force can be derived using the acoustic streaming theory. The calculated SAW streaming force is found to be very large and strong enough to expel a droplet from a liquid surface.

Ethnicity has been found to influence urinary testosterone glucuronide to epitestosterone glucuronide (T/E) ratios among athletes. Uridine diphospho-glucuronosyltransferase 2B17 (UGT2B17) is the most active enzyme in testosterone glucuronidation. UGT2B17 polymorphism analysis is rarely performed in Japanese athletes, and the influence of testosterone administration on steroid profiles and carbon isotope ratios, according to gene polymorphisms, in Asians remains unknown. The prevalence of UGT2B17 genotypes and urinary androgenic steroid profiles, classified according to UGT2B17 genotypes, was investigated in Japanese athletes (255 male and 256 female). Testosterone enanthate (100 mg) was administered intramuscularly to Japanese female volunteers (del/del: n = 6, del/ins: n = 3, ins/ins: n = 1). The distribution rates of the UGT2B17 del/del genotype in Japanese male and female athletes were 74.5% and 60.2%, respectively. The ins/ins genotype was detected in only three male (1.2%) and seven female (2.7%) athletes. The prevalence of the UGT2B17 deletion genotype was extremely high in Japanese athletes. The T/E ratio in the del/del group was significantly lower than that in the other groups. After testosterone was administered to female volunteers, the T/E ratios for the del/del individuals failed to reach the positivity criterion of 4. By contrast, in all of the del/del subjects, the gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS) analysis successfully fulfilled the positivity criterion. The overall result has demonstrated the limited effectiveness of population-based T/E ratios in screening tests for testosterone use. Subject-based steroid profiling with UGT2B17 genotyping will be an effective strategy for detecting testosterone misuse.