into the patient. PCR will be performed to monitor for this 
unlikely event. 
The use of aminoglycoside antibiotics . The neomycin resistance 
gene, which encodes neomycin phosphotransferase (NPT) , 
phosphorylates the 3' hydroxyl group of the aminohexose I of 
neomycin and its analogues, inactivating the antibiotic. While 
amikacin may be inactivated by this enzyme, gentamicin and 
tobramycin do not contain an hydroxyl at the 3' position and are 
not inactivated. Therefore, introduction of the NeoR gene would 
not exclude the use of aminoglycosides or any other conventional 
antibiotic that may be needed in the clinical management of these 
patients . 
Although risks to the patient exist in this study, they 
would appear to be minimal, and the escalating dose nature of 
this study should minimize the risks to any individual patient. 
Because these patients have limited life expectancy from their 
advanced cancer, these risks are thought to be justified, 
considering the potential therapeutic benefit. 
Recombinant DNA Research, Volume 17 
[723] 
