Detection of ornithine transcarbamylase deficiency heterozygotes by measuring of urinary uracil.

The importance of detecting heterozygosity for X-linked ornithine transcarbamylase deficiency is well known. Although the DNA analysis and the allopurinol loading tests are commonly used for this purpose, both methods require complicated procedures. In order to establish a simple test for detecting female heterozygotes, we examined the uracil and orotic acid in single-voided urine samples from 70 healthy women, and from 12 asymptomatic females with ornithine transcarbamylase deficiency. Based on the results of healthy women, we were able to determine a screening cut-off line of 11.9 micromol/mmol creatinine (mean +/- 1SD in logarithmic form) for uracil. Using this cut-off line, the sensitivity of OCT heterozygotes was 100%. We were also able to establish a second cut-off line of 28.9 micromol/mmol creatinine (mean +/- 3SD in logarithmic form) for diagnosis. Using this second cut-off line, the specificity of OCT heterozygotes was 100%. Our study has shown that the measurement of urinary uracil is a relatively simple and effective method for detecting female heterozygotes.

Decrease of N-acetylaspartate after ACTH therapy in patients with infantile spasms.

Apparent brain atrophy has been frequently observed at CT and MRI after ACTH therapy in patients with infantile spasms. There are several hypotheses to explain ACTH-induced brain shrinkage: 1) a catabolic effect of ACTH on brain tissue, 2) a mineralocorticoid effect resulting in a loss of water and 3) an increase in cerebrospinal fluid (CSF) pressure compressing the brain. An average of 0.21 +/- 0.03 mg/kg of ACTH was administered to nine patients over a period of 14 to 17 days. Water content and concentrations of N-acetylaspartate (NAA), creatine and phosphocreatine (Cr + PCr), and choline (Cho) were measured before, immediately after, and several months after the ACTH therapy by using in-vivo 1H magnetic resonance spectroscopy (MRS). Only NAA concentration exhibited a significant change during the study (6.6 +/- 1.5 mmol/kg, 5.4 +/- 1.1, and 7.0 +/- 1.5, p = 0.017). There was no significant change in Cr + PCr, in Cho, or in water content. These data suggest catabolic effects of ACTH on brain tissue, such as cell loss, decrease in NAA synthesis in mitochondria, and leakage of NAA from cell membrane.

[Long-term follow-up of tetralogy of Fallot corrected by Okamura's method under simple deep hypothermia].

Corrective surgeries for TOF (Tetralogy of Fallot) were performed in 350 patients from 1967 to 1983 by Okamura's method under simple deep hypothermia. Radical operations were done in all patients, including very young children. The operative techniques had several differences from the standard procedure. Patients were operated on without any extracorporeal perfusion, the VSD was closed by a patch which was attached firmly to the margin of VSD using cross mattress sutures and the right ventricular outflow tract was dilated by infundibular myectomy only, with no use of outflow-patch-plasty. One hundred ten out of 350 patients were investigated by questionnaire and their responses showed that they had few long-term problems. ECG, X-ray, echocardiography and stress test by treadmill were performed in 26 cases. They were divided into two groups by the presence or absence of pulmonary regurgitation (PR). The CTR of the PR (+) group was larger than the PR (-) group (p less than 0.05). There was no statistical difference in cardiac function between the two groups. Few arrhythmias were observed during the exercise test. No residual shunts were found in any of the cases. The occurrence of PR was relatively rare in those who were operated on before their second birthdays. These results suggest that our surgical techniques under simple deep hypothermia are adequate to correct TOF.