Masaaki Arima

Ultrasonographically demonstrated nutcracker phenomenon: alternative to angiography.

We report on a child with nutcracker phenomenon, which is a possible cause of intermittent gross haematuria of unknown origin. Early serial ultrasound examinations can demonstraste the lesions.The merits and demerits of conventional angiographic imaging are also discussed.

Renal Growth and Progression of Reflux Nephropathy in Children with Vesicoureteral Reflux

We analyzed renal growth and development of renal scars in 754 children with primary and 169 with secondary vesicoureteral reflux. The incidence of a small kidney was 15.5 per cent in the primary and 24.1 per cent in the secondary groups. About three-fourths of the small kidneys remained small from the first examination through followup. Catch-up renal growth was only exceptional. New scars or progression of previous scarring was observed in 7.4 and 30 per cent of the primary and secondary groups, respectively. Factors that promote formation of new scars are high grade vesicoureteral reflux, recurrent urinary tract infections and abnormal bladder function that results in high pressure reflux. We emphasized the importance of precise examination of the lower urinary tract. An early antireflux operation should be performed on children with severe reflux or recurrent urinary tract infections.

The immunosuppressive mode of action of mizoribine.

Mizoribine (MIZ) suppressed the mitogen response and mixed lymphocyte reaction (MLR) significantly at doses of 100 micrograms/ml and 10 micrograms/ml in a dose-response analysis. The 50% inhibition dose (ID50) was between 10 micrograms/ml and 1.0 microgram/ml, both in the mitogen response and MLR. In a kinetic study of the MLR, the degree of suppression with MIZ at a given dosage was essentially the same as the degree of suppression observed in the dose-response analysis when MIZ was added to MLR cultures from day 0 to day 4. In addition, MLR was more susceptible to the suppressive activity of MIZ at 100 micrograms/ml when MIZ was added near the peak of lymphocyte proliferation. This experiment also showed that MLR suppression induced by MIZ at 10 micrograms/ml was reversible and MLR activity had completely recovered 6-8 hr after its removal. MIZ had no inhibitory action on MLR-derived cytotoxic cells or the effector phase of cell mediated lymphocytotoxicity. These results clearly demonstrate that MIZ suppresses lymphoproliferation, but has no effect on the recognition phase or effector phase of cytotoxic lymphocytes.

Vesicoureteral reflux in infants under one year old Follow-up study and consideration on development of renal scarring

In an attempt to clarify reflux nephropathy (RN), 67 infants aged under one year with vesicoureteral reflux (VUR) were retrospectively classified into two groups, non-surgical and surgical. They were evaluated on VUR grading, VUR spontaneous cessation rate, and incidence of scarring. As a whole, spontaneous cessation rate was 61 percent. The cessation rate was higher for infants with lower VUR grading. The average age at cessation was 2.5 years. Some patients showed no scarring at presentation despite severe VUR. However, most cases of renal scarrings at the time of presentation belonged to grade IV or V. Scarring advanced in 3 kidneys of the non-surgical group and in 13 kidneys of the surgical group. Of these 16 kidneys, 7 were rated as grade IV and 9 as grade V. An association between development of scarring and recurrent urinary tract infections was suggested.

Combined Cisplatin and Radiation Therapy in Patients with Invasive Bladder Cancer

Thirty-five patients with T2–T4 invasive bladder cancer were treated with combined cisplatin and radiation therapy. In 18 patients radical cystectomy was performed after the combined therapy. In the other 17 patients radical cystectomy could not be performed for various reasons. Pathological examination of the cystectomy specimens showed down-staging in 66.7% and no residual tumour in 33.3%. These results suggest a synergistic action of cisplatin and radiation. Side effects were not severe and were well tolerated. This combined therapy of cisplatin and radiation is very effective for invasive bladder cancer.

Clinical analysis of the small kidney associated with VUR

Analysis was performed on the clinical features of children with VUR who had one or two kidneys that were at least—2 SD smaller than normal for age of its renal ratio. The prevalence of the small kidney was 15.6% (97/623 children). Of 107 small kidneys, 87 (82%) were associated with moderate (grade IV) to severe (grade V) reflux and renal scarring was evident on 95 kidneys (88%). About half of the kidneys were diagnosed as scarred atrophy and 40% as congenital hypoplasia. The renal growth after antireflux surgery was evaluated by the change of the renal ratio and it was found that about three-fourths remained small during the pre- and postoperative periods. Accelerated growth was only exceptional.

A simple modification using the appendix as efferent limb in ileocolonic reservoir (Mainz pouch)

The appendix was used as an efferent limb of the ileocolonic pouch (Mainz pouch) in two patients who underwent radical cystectomy for invasive bladder cancer. The pouch has a low pressure character and sufficient capacity as well as complete continence. This procedure is relatively simple to perform and considered to be a useful modification of ileocolonic pouch.