K Hashizume

Naked plasmid DNA transfer to the porcine liver using rapid injection with large volume.

The naked plasmid DNA transfer method of rapid injection with large volume has been useful for gene therapy in experimental study. However, only small animals like rodents have usually been reported on. In this study, the authors attempted to transfect naked plasmid DNA to the porcine liver by modified hydrodynamic method. We decided to transfer plasmid DNA to a part of the liver using the angio-catheter to reduce the liver damage. To discern the condition of injection, naked plasmid DNA-encoding green fluorescent protein (GFP) was transferred for use as a marker gene. The GFP gene expression was markedly observed in gene-transferred pig livers. In large animals, not only the naked gene quantity, the solution volume containing the plasmid DNA and the injection speed, but also the additional treatments of the portal vein and the hepatic artery preparation were crucial. We found that the following injection condition were needed: plasmid DNA, 3 mg; the solution volume, 150 ml and the injection speed, 5 ml/s. The portal vein and the hepatic artery were clamped during gene delivery and the blood flow of the portal vein was flushed out using normal saline. Cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4-Ig) gene was used to test for secretory protein. CTLA4-Ig gene was injected with a large volume of solution via the hepatic vein to the left outer lobe of the liver selectively. CTLA4-Ig was detected in the pig blood at a maximum serum level of 161.7 ng/ml 1 day after gene transfer, and the CTLA4-Ig was detected for several weeks. Our new technique of inserting a catheter into only a selected portion of the liver reduced liver toxicity and increased gene transfer efficiency. This is the first report of successful gene transfer, using a hydrodynamic method, to the segmental liver in pigs, and achieved more than enough secretory protein for the clinically therapeutic level in pigs.

Portal venoplasty for recipients in living-related liver transplantation.

BACKGROUND In living-related liver transplantation (LRLT) in small children, standard end-to-end portal vein (PV) anastomosis is usually difficult because of a inadequate total PV length, or because of a size mismatch between the graft and the recipient PV. In this report, we present our new portal venoplasty technique for the recipient PV. METHODS After dissection of the recipient PV, the wall between the right and left branches of the PV is severed longitudinally as in the branch patch technique. The anterior and posterior edges of both branches are joined using running sutures, to form a longer and wider PV for anastomosis. RESULTS This new portal venoplasty technique was used in 7 of 28 child cases, and gave good results without thrombosis or other complications. CONCLUSIONS Our new portal venoplasty technique is useful in LRLT in small children when the recipient or graft PV is not long enough.

Arterial waveforms on doppler ultrasonography predicting or supporting hepatic arterial thrombosis in liver transplantation

HEPATIC arterial thrombosis (HAT) is a major cause of patient morbidity and graft loss in liver transplantation. HAT should be diagnosed before the development of liver parenchymal or bile duct damage. Early diagnosis and treatment are essential to salvage grafts. Doppler ultrasound (US) is a useful tool to diagnose HAT. HAT is diagnosed when arterial flow signals are not detected in the graft. However, waveforms on Doppler US predicting or suggesting HAT are not fully understood. In this study, we investigated whether the waveforms on Doppler US can predict or suggest HAT.

Increase in natural killer cell activity following living‐related liver transplantation

Abstract We monitored the serial changes of natural killer cell (NK) activity in eight recipients of living‐related liver transplantation. The HLA types of all eight patients were haplotypically identical with those of their donors. Tacrolimus and methylprednisolone were used for immunosuppression. The NK activity before transplantation was 24.1 ± 20.2 % which is surprisingly low when compared with the value for normal individuals (67.7 ± 13.2%, P < 0.01) or a liver dysfunction group (49.4 ± 21.9%, P < 0.05). Serial changes in NK activity revealed a minimum of 6.1 ± 3.6% 1 week after transplantation, gradually increasing to 49.2 ± 12.5 % at 2 months after transplantation. These results suggest that the diseased liver might play an important role in the suppression of NK activity.