LOWE'S SYNDROME: Absence of Amino Acid Transport Defect in Cultured Fibroblasts

Transport of lysine and glycine was studied in cultured fibroblasts of a patient with Lowe's oculocerebrorenal syndrome. Although patients with this syndrome demonstrate renal and intestinal amino acid transport defects, no abnormality was found in our study.     

Implantation Techniques of Antitachycardia Devices

Implantation of a defibrillator may be by a mixed technique of transvenous leads and subcostal thoracotomy. An alternative approach is placement of all defibrillator leads and possible pacemaker leads via median sternotomy. All sensing leads, either for a defibrillator or a pacemaker, should be bipolar to provide maximal rejection of interference signals. Interpretation of the electrogram requires analysis of the pathologic electrogram to distinguish it from the "normal" electrogram for that patient and may require several leads to determine the activation sequence; which will allow diagnosis of a tachycardia in a fashion similar to that performed by a human observer.     

A Decade of Nuclear Pacing

In April, 1973, a decade-long study was begun on nuclear-powered pacemakers. The first 15 of these were designed by the Numec Corporation under a contract from the United States Atomic Energy Commission. Altogether 151 units powered by the isotope plutonium 238 were implanted in 131 patients; the pacemakers of 4 different manufacturers were used. The last nuclear pacemaker was implanted in January, 1983. The actuarial survival at 10 years was 92%, meeting the original performance goal of the Commission of 90%. Ninety pulse generators are still in service today; 25 patients have died and 36 pulse generators have been replaced with non-nuclear units. The most common indication for replacement was an inappropriate pacing mode. This high reliability and superior performance suggest that continued use of a radioisotopic power source is justified, particularly if combined with the electronic circuits of today's dual-chambered, multiprogrammable, and multifunctional pacemakers.