In order to elucidate the mechanism of shock wave injury in biological tissues, the mechanical damage of aluminum foils and the hyperechoic region, in the focal zone were studied. The shock waves were produced by a specially designed piezo-ceramic (overhead and water-bag type) generator. For focus localization an ultrasonic sector probe was used. On aluminum foils numerous pits were observed circumferentially around the central major deformity. The pits were formed not only in the focal region but also in the pre-focal region. The hyperechoic region, which appeared as a cloudy area on an ultrasound screen in the focal region, moved and disappeared after more than 5 sec. The numerical simulation indicated that the maximum flow speed reached 30 meter per second, and the direction of the flow was both axial and radial.

On an ultrasonic imaging system a hyperechoic region was observed in a focal area of fucused shock waves in the dog kidney. This study was performed to learn whether cavitation bubbles are responsible for this hyperechoic region.The ultrasonic images in water of varying temperatures were not markedly different. In the flowing stream of distilled water, the stream was demonstrated as a hyperechoic region only with a mixture of air bubbles. Streams of 5%–50% glucose solutions were also demonstrated as a hyperechoic region. However, such concentration changes in living tissue, as well as thermal changes, are hardly thought to be induced.The holographic interferometry showed that the cavitation bubbles remained for more than 500 msec. in the focal area in water. This finding indicate that the bubble can remain for longer period than previously supposed.These results support the contentions that cavitation bubbles are responsible for the hyperechoic region in the kidney in situ.

In the animal experiments, glomerular filtration rate (GFR) values were estimated from the urinary response to the intravenously administrated iopamidol. By introducing some reasonable assumptions, mass balance equations about the contrast medium were transformed and GFR was defined as the ratio of logarithm of urinary concentration by time. Urinary concentrations were determined by measuring the photodensity on the X-ray film of urine specimens. Obtained values of GFR were well fitted to those obtained by the analysis of the plasma disappearance curve. The advantage of this method is that measurement of urinary volume is not necessary.

Biological evidence of renal arterial wall damage induced by the microjet due to shock wave‐cavitation bubble interaction was demonstrated in living dog kidneys. We also intended to clarify the mechanism of renal tissue damage and the effects of different conditions of shock wave exposure (peak pressure of focused area, number of shots, exposure rate) on the renal tissue damage in comparison to stone disintegration.Disruption of arterial wall was the most remarkable histological change in the focused area of the kidneys. This lesion appeared as if the wall had been punctured by a needle. Large hematoma formation in the renal parenchym, and interstitial hemorrhage seemed to be the results of the arterial lesion. This arterial disorder also led to ischemic necrosis of the tubules surrounding the hematoma. Micro‐angiographic examination of extracted kidneys also proved such arterial puncture lesions and ischemic lesions.The number of shots required for model stone disintegration was not inversely proportional to peak pressure. It decreased markedly when peak pressure was above 700 bar. Similarly thenumber of shots for hematoma formation was not inversely proportional to peak pressure, however, this decreased markedly above 500 bar. These results suggested that a hematoma could be formed under a lower peak pressure than that required for stone disintegration.

N-acetyl-beta-D-glucosaminidase (NAG) is a lysosomal enzyme predominantly located in renal proximal tubules. In idiopathic hypoparathyroidism (IHP), 100 Units of human PTH (1-34) increased urinary excretion of NAG from 0.029 +/- 0.027 to 0.173 +/- 0.035 U/lGF (p less than 0.05) in two patients before treatment and from 0.025 +/- 0.004 to 0.189 +/- 0.092U/lGF (p less than 0.02) in four patients during treatment with active vitamin D3 (1,25(OH)2D3 or 1 alpha OHD3). In pseudohypoparathyroidism (PHP), PTH did not significantly increase the urinary excretion of NAG in one patient with before treatment (0.048 to 0.025 U/lGF) and four patients during treatment with active vitamin D3 (0.018 +/- 0.008 to 0.036 +/- 0.015 U/lGF). Increase in urinary excretion of NAG after injection of PTH may be a new indicator of renal effect of PTH.

The status of the ion-guide isotope separator on-line at the Tohoku University Cyclotron is reported. The optimum ion-guide parameters were determined from test experiments using atomic and molecular ions ionized with an electric discharge inside the target chamber as well as using 64Ga(T12 = 2.6 m) ions produced by the 64Zn(p, n) reaction. Using the present system together with a ΔE−E plastic counter telescope and a germanium detector we identified 16 short-lived nuclei including the first mass-separated nuclei 57Cu and 45V. The efficiency of mass separation for 64Ga was ϵ ∼ 1%, where ϵ is defined as the number of atoms collected at the end of the separator divided by that recoiling from the target. Application of IGISOL to nuclear physics is being performed for nuclei in the f72-P32 shell regions and medium-mass neutron-rich nuclei produced by the proton-induced fission reaction with a uranium target.

The half‐lives of Tz=−1/2 mirror nuclei in the f7/2‐shell region were measured with a new on‐line separator, IGISOL of Tohoku University. The deduced experimental Gamow‐Teller (GT) matrix elements were compared with the results of large‐scale shell‐model calculations. As an average quenching factor of the GT matrix elements for the mirror β‐decay in the f7/2‐shell a value of 0.844±0.042 (simple average) was obtained.

An ion-guide isotope separator on-line (IGISOL) has been constructed at INS. The overall efficiency of the IGISOL has been measured to be about 2%. An effect of the plasma formed along the path of the cyclotron beam was investigated by using the 27Al(α, 2pn)28Al, 19F(12C, 2pn)28Al and 12C(19F, 2pn)28Al reactions. Decrease of the relative efficiency with the increase of the beam intensity has been observed, indicating evidence for the plasma effect for the first time.