Yasushi Katayama

Does Gadolinium-diethylene triamine pentaacetic acid enhanced MRI of kidney represent tissue concentration of contrast media in the kidney? In vivo and in vitro study

Although Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in magnetic resonance imaging (MRI), it is known that contrast enhancement effect is not uniform if the concentration of Gd-DTPA increases beyond some levels. In this study, to evaluate the proper pulse sequences for dynamic MRI in the human kidney, the concentration of Gd-DTPA was quantitatively measured by inductively coupled plasma (ICP) emission spectrometry in human biological samples after administration of Gd-DTPA. The signal intensity of MRI in the solutions of several concentrations of Gd-DTPA was measured. The results were that in using a low magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 mumol/g under saturation recovery sequences (flip angle = 60 degrees or 90 degrees). Using a high magnetic field apparatus, signal intensity linearly correlated with the concentration of Gd-DTPA between 0 and 2.0 or 3.0 mumol/g under spin-echo or gradient-echo sequences. Gd-DTPA concentration of the renal cortex ranged from 0.132 to 0.152 mumol/g tissue at 5 min after IV injection of Gd-DTPA 0.05 mmol/kg body weight in six patients with adrenal tumor or renal cell cancer, and one patient with both urinary bladder cancer and prostatic cancer. Six of the patients showed normal renal function and the other had renal insufficiency (GFR = 25 ml/min/1.48 m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Value of dimercaptosuccinic acid single photon emission computed tomography and magnetic resonance imaging in detecting renal injury in pediatric patients with vesicoureteral reflux : comparison with dimercaptosuccinic acid planar scintigraphy and intravenous pyelography

The value of 99mTc-dimercaptosuccinic acid (DMSA) planar renal scintigraphy, DMSA single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) in the assessment of renal injury related to vesicoureteral reflux (VUR) was examined in 60 kidneys of 32 pediatric patients (28 bilateral, 4 unilateral) with primary VUR. The results were: (1) detection of minor renal lesions was best with MRI, then DMSA-planar and DMSA-SPECT, and (2) in comparing the positive rate, DMSA-SPECT (85%) and MRI (83.3%) were superior to intravenous pyelography (55%) and DMSA-planar scintigraphy (65%). These results suggest that DMSA-SPECT or MRI may be more sensitive than DMSA-planar scintigraphy and intravenous pyelography in detecting renal injury related to VUR in pediatric patients.

Changes in urinary excretion of endothelin-1-like immunoreactivity before and after unilateral nephrectomy in humans. Comparison with other urinary parameters and unilateral adrenalectomy.

To assess the value of endothelin-1 (ET-1) as a parameter of renal functional overload and the process of hyperfiltration, urinary excretion of ET-1-like immunoreactivity (U-ET-1) and urinary excretion of other parameters [beta 2-microglobulin (beta 2-MG), N-acetyl-beta-D-glucosaminidase (NAG), albumin (Alb) and 24-hour creatinine clearance (Ccr24)] were measured before, 1, 2 and 7 days after unilateral nephrectomy in 15 patients with unilateral renal lesions (renal cell cancer, renal pelvic cancer, ureteral cancer and renal tuberculosis) and after unilateral adrenalectomy in 5 patients with adrenal lesions. In the nephrectomy group (NX), Ccr24 significantly decreased at 1 and 2 days after the operation, but the other 4 parameters significantly increased after the operation as compared to preoperative values. In the adrenalectomy group (ADX), neither Ccr24 nor ET-1/Cr showed any change after the operation, but the other 3 parameters (beta 2-MG/Cr, NAG/Cr and Alb/Cr) significantly increased. Comparing the NX and ADX groups, both ET-1/Cr and beta 2-MG/Cr in NX were significantly higher than in ADX after the operation. On the other hand, neither NAG/Cr nor Alb/Cr in NX differed from values in ADX. Comparing ET-1/Cr and other parameters, only beta 2-MG showed a positive significant correlation. These results suggest that U-ET-1 may be an indicator of functional overload of the kidney.

Primary Localized Amyloidosis of the Bladder: A Case of AL (λ) Amyloid Protein and Combination Therapy Using Dimethyl Sulfoxide and Cepharanthin

We report a case of primary localized amyloidosis of the bladder with amyloid deposits which was characterized as being of immunoglobulin light chain origin (AL) including lambda type (A lambda) and P component (AP) using the KMnO4 pretreatment method and immunohistochemical procedures. The patient was treated successfully with intravesical dimethyl sulfoxide instillation and oral administration of high-dose cepharanthin after transurethral resection. Combination therapy with dimethyl sulfoxide and cepharanthin was shown to be useful for primary localized amyloidosis of the bladder.

Value of Urinary Endothelin-1 in Patients with Primary Vesicoureteral Reflux

By using a radioimmunoassay specific for endothelin-1 (ET-1), we measured urinary excretion of ET-1-like immunoreactivity (LI) in 63 spot urine samples of 48 patients with primary vesicoureteral reflux (VUR). And also, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (beta-2-MG), microalbumin (Alb) and creatinine (Cr) were measured. There was no significant correlation in any of the pairs ET-1 and NAG, ET-1 and beta 2-MG, and ET-1 and Alb. Comparing the grade of reflux according to the International Classification with urinary ET-1, urinary ET-1/Cr levels in patients with grade 2, 3 and 4 VUR were higher than normal, and the ratio of more than normal urinary ET-1/Cr increased in proportion to the grade of reflux, but it conversely decreased in grade 5. In conclusion, urinary ET-1 may be an indicator of renal tubular injury in patients with primary VUR, and its meaning may be different from conventional urinary parameters.

Application of flexible renoureteroscope for antegrade urethroscopy in the treatment of congenital anterior urethral valve

Antegrade urethroscopy was performed through a cystostomy using a 10.8-fr caliber flexible renoureteroscope in 4 children (aged 2 years and 8 months, 2 months, 14 years and 1 month) with anterior urethral valve. The anatomy of the valves as well as their destruction after transurethral resection (TUR) were well visualized by antegrade urethroscopy. This technique was helpful in performing TUR-valve, after which the findings of voiding cystourethrography in every case and the findings of uroflowmetry in the elder 2 cases showed remarkable improvement. This technique is relatively simple to perform and is thought to be one of the best methods to treat anterior urethral valve. This technique is also applicable to other lower urinary tract lesions in children.

Evaluation of upper urinary tract dynamics by diuresis renography in patients receiving urinary reservoir operation : comparison of full and empty reservoir

Upper urinary tract dynamics was evaluated using diuresis renography during full and empty reservoir in 14 patients (11 men, 3 women, 13-70 years old) with intestinal urinary reservoir or intestinal bladder augmentation. Types of operation were Mainz pouch urinary diversion 5, Mainz neobladder to urethra, 5, Kock pouch urinary diversion 2, and Mainz bladder augmentation 2. Diuresis renography was performed using 99mTc-DTPA and furosemide during full and empty reservoir, and several parameters (Tmax, T75, T50, GFR) in addition to the patterns of renogram were evaluated. In the normal control, none of the parameters of the diuresis renogram with full bladder differed from those with empty bladder. In 5 of 14 patients, abnormal waves on cystometry (CMG) were found, and in 4 of these 5 patients, the patterns of diuresis renogram of full reservoir were worse than those of empty reservoir. However, the patterns of diuresis renogram of full reservoir were not different from those of empty reservoir in 9 patients without abnormal waves on CMG. In conclusion, renal injury may easily occur in patients with intestinal reservoir and abnormal waves on CMG.

Incidence of Pouch Stones and Risk Factors for Urolithiasis in Patients with Continent Urinary Diversion or Neobladder Using Intestine

Urinary risk factors and inhibiting factors for urolithiasis, such as oxalate, calcium, phosphate, uric acid, citrate, and magnesium, were examined in 12 patients receiving continent urinary diversion, neobladder, or augmentation cystoplasty using intestine. These data were compared with the incidence of pouch stone formation. Ten (83.3%) of 12 patients had at least one risk factor, and 5 (41.7%) of 12 had two or more risk factors. Pouch stone developed in 4 (80%) of 5 patients with two or more risk factors, and in none of 7 patients with one or zero risk factors. The incidence of pouch stone in the former group was significantly higher than in the latter group. These results suggest that urinary reservoir operations should not be performed in patients with two or more risk factors for urolithiasis.

Measurement of urinary endothelin-1-like immunoreactivity and comparison with other urinary parameters in patients with primary vesicoureteral reflux : a preliminary report

By using a radioimmunoassay specific for endothelin-1 (ET-1), we measured urinary excretion of ET-1-like immunoreactivity in 63 spot urine samples of 48 patients with primary vesicoureteral reflux (VUR). Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (beta 2-MG), microalbumin (Alb), and creatinine (Cr) were also measured. There was no significant correlation in any pairs of ET-1 and NAG, ET-1 and beta 2-MG or ET-1 and Alb. In patients with grade 2, grade 3, and grade 4 VUR, urinary ET-1/Cr was significantly higher than normal (p < 0.05). Comparing the grade of reflux according to the International Classification with urinary ET-1/Cr, the ratio of more than normal urinary ET-1/Cr increased in proportion to the grade of reflux, but it conversely decreased in grade 5. In conclusion, urinary ET-1 may be an indicator of distal renal tubular or collecting duct injury in patients with primary VUR.

Assessment of high-energy phosphorus compounds in the rat kidney by in situ31P nuclear magnetic resonance spectroscopy: effect of ischemia and furosemide

Summary31P nuclear magnetic resonance (NMR) spectroscopy of the in situ rat kidney was performed by a surface coil method, and the effects of ischemia and furosemide infusion were assessed.31P NMR spectra of the kidney subjected to 30 min of ischemia returned completely to the pre-ischemic level after 60 min of reperfusion. But the31P NMR spectra after 60 min of ischemia did not recover, even after 120 min of reperfusion. Levels of β-ATP and inorganic phosphate (Pi) decreased and the chemical shift of Pi increased after intravenous infusion of furosemide. This increase in chemical shift might signal an alkalotic change in intracellular pH. Furosemide infusion prior to ischemia is thought to protect the kidney from injury induced by 60 min of warm ischemia. The chemical shift of Pi returned to the pre-ischemic level earlier than β-ATP and Pi. In conclusion, according to the findings of31P NMR spectroscopy, furosemide infusion prior to ischemia may be effective in protecting the kidney against ischemic injury. But the change in Pi peak and the causes of the dissociation of Pi and β-ATP should be examined further.