plates and exposed to the human LDL receptor expressing retrovirus (#132-10) 48 hrs after 
seeding. Following 12-16 hrs of exposure to virus the cells were washed and harvested. A total 
of 2 x 10 9 cells were recovered with 98 % overall viability. Analysis of several plates of cells 
demonstrated gene transfer and high level of LDL receptor expression in 30 % of the cells. The 
animal was taken to the fluoroscopy suite and a portal venogram was done demonstrating patency 
and the correct placement of the catheter as well as a completely patent portal circulation. The 
hepatocytes were infused into the catheter in two aliquots as described above without apparent 
toxicity. Cell infusion was associated with a small increase in portal pressure which was 
transient (see Table 3). 
Table 3. Summary of First Baboon Experiment 
1 . Animal - 17 kg male baboon 
2 . Liver resection and isolation of hepatocytes (day 0) 
- left lateral segment removed (35 gm) 
- Broviac catheter placed in inferior mesenteric vein 
(portal pressure - 7 cm H 2 O) 
- 0.7 x 10 9 cells isolated with 98% viability 
- cells plated onto 225 10 cm plates 
- animal tolerated procedure extremely well 
3. 
4. 
LDL receptor transduction of the cultured hepatocytes 
- Dil-LDL assay - high level overexpression of LDL receptor in 30% of the cells 
Harvest and infusion of hepatocytes (day 3) 
- Hepatocytes harvested in two batchs: 
Batch #1 - 1.2 x 10 9 with 97 % viability 
Batch #2 - 0.8 x 10 9 with 98% viability 
- Hepatocytes infused 
Catheter and portal circulation fully patent by portal venography 
Cells Infused in two aliquots without complication 
Summary of portal pressures 
initial catheter placement (day 0) 7 cm H 2 O 
prior to infusion #1 (day 3) 4 cm H 2 O 
after infusion #1 (day 3) 10 cm H 2 O 
after infusion #2 (day 3) 14 cm H 2 O 
at laporotomy (day 13) 9 cm H 2 O 
- animal tolerated the procedure extremely well 
5. Laporotomy (day 13) 
-Catheter found detached from mesenteric vein, no gross pathology 
-portal venogram demonstrated fully patent portal vein and intrahepatic 
portal venous branches with no evidence of intraluminal filling defects 
-pressure - 9 cm H 2 O 
-Needle biopsy of liver performed (no histopathology noted) 
In the human protocol we would have withdrawn the catheter immediately after the 
infusion of cells. In the baboon experiment, we elected to keep the catheter in place for a longer 
period of time to determine its long term stability and patency. This was complicated by the fact 
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Recombinant DNA Research, Volume 15 
