Renal artery stenosis in pediatric transplant recipients.

From 1967 through 1985, 400 cadaveric transplants were performed at Children Hospital of Los Angeles. Of these 400, 31 were later identified as having renal artery stenosis. No live related graft developed RAS. Of the 31 grafts, 11 were from donors less than 2 years of age. The major feature suggesting stenosis was hypertension; either persistent or a sudden exacerbation often associated with hypertensive encephalopathy. In individuals with hypertension without obvious cause, renal angiography should be promptly conducted under controlled conditions to avoid complications. The stenotic lesion involved 13 end-to-end and 19 end-to-side arterial anastomoses. Surgery for revascularization of RAS was performed in 21 of 31 with success or improvement in 14, no change in 2, and graft loss in 5. Percutaneous transluminal angioplasty was performed in 4. Two were unsuccessful, 1 was successful and 1 graft was lost. The 7 remaining patients were treated medically.

Childhood pheochromocytoma: treatment with alpha methyl tyrosine for resistant hypertension.

A 12-year-old boy with a norepinephrine-secreting pheochromocytoma that caused hypertension resistant to oral alpha adrenergic blockade is reported. Resistance to alpha adrenergic blocking agents developed when the patient's daily propranolol dosage was lowered from 10 to 1 mg/kg. Subsequently, alpha methyl tyrosine, an inhibitor of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, controlled the patient's blood pressure and was associated with reduction in total urinary catecholamine excretion. Norepinephrine content of the tumor and uninvolved adrenal gland removal at surgery was reduced. These findings confirm that alpha methyl tyrosine inhibited in vivo synthesis of catecholamines.

Cyclophosphamide in the treatment of idiopathic nephrotic syndrome.

Fifty-three patients 3 1/2 to 20 years of age with steroid-dependent idiopathic nephrotic syndrome (INS) were treated with cyclophosphamide and prednisone. Two dosage schedules were used: a short course (SC) at 3 to 5 mg/kg/day for six to eight weeks and a longer course (LC) at 3 to 5 mg/kg/day for eight weeks followed by 1.5 to 2.5 mg/kg for an additional four weeks. Prednisone was administered concurrently at 50 to 75 mg/sq M every other day. Twenty-nine patients were in the SC group and 24 in the LC group. The two groups did not differ significantly as to age at onset of idiopathic nephrosis nor as to the duration of the INS prior to cyclophosphamide therapy. All patients were followed for a minimum of 42 months after cyclophosphamide therapy. The SC was associated with a higher relapse rate during the first year than the LC (42% and 8% respectively, .01 larger than P less than .025). At 42 months 63% of the LC group were in remission compared with 21% in the SC group.

Gonadal function in children with nephrosis treated with cyclophosphamide.

Conadal function was evaluated in 23 boys and 11 girls treated with cyclophosphamide, 2 to 5 mg/kg/day for periods of 1.5 to 6 months. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels were determined by radioimmunoassay. All 16 boys treated when prepubertal or during early puberty had normal, FSH, LH, and testosterone levels. Testicular biopsy was performed in five of the 16, and was abnormal in four and normal in one. Sperm count was normal in two other patients. The remaining seven boys were treated when pubertal; all have decreased spermatogenesis, and five of them have increased FSH levELS. The LH and testosterone levels were normal. No evidence of gonadal dysfunction was detected in any of the girls. Of four patients treated when postpubertal, three have become pregnant.