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PIXE, Particle Induced X-ray Emission, is a Powerful, multi-elemental analysis method which has many distinguishing features and has been used in varies research fields. Recently the method of applying baby cyclotrons for nuclear medicine to PIXE has been developed. This enables us to study biomedical phenomena from the physical point of view. Mouse bone marrow stromal cells were transferred bacterial β -galactosidase gene (LacZ gene) by murine retroviral vectors. Analysis of the bone marrow stromal cells with the LacZ gene by PIXE revealed remarkable changes of intracellular trace elements compared with the normal control cells. These results indicate that gene transfer by retroviral vectors may bring about a dynamic change of intracellular circumstances of the target cell.

The purpose of this study was to investigate the effectiveness of human bone morphogenetic protein-2 (BMP-2) expressing adenoviral vector in vivo. The day before vector injection, immunosuppressant FK506 was given subcutaneously to each rat at doses of 12 mg/kg (Group I), 6 mg/kg (Group II) and 3 mg/kg (Group III). FK506 was not administered to the six rats of the control group. Twenty-five liters of AXCAOBMP-2 (3.93 × 10⁹ pfu/ml) were injected into the right calf muscle of all rats. On day 21 after vector injection, all groups were investigated radiologically, histologically, and biochemically. Osteoinduction was seen in the AxCAOBMP-2-injected groups with immunosuppression. However, no bone formation was observed in the control group. These findings suggest that AxCAOBMP-2 has the potential of osteoinduction under transient immunosuppression. AxCAOBMP-2 may be useful for future clinical application in bone reconstruction, if host immunity response can be regulated.

The objective of this paper was to study in vitro transfection of tendon cells and adherence of transfected cells to different tendon surfaces. Achilles tendon fibroblasts from 2-month-old New Zealand white rabbits were cultured to confluence, after which the cells were transfected by an adenovirus carrying either the β-galactosidase reporter gene or the green fluorescent protein (GFP) gene at multiplicities of infection (MOIs) of 50, 100, or 500. Two days later, the cells were transplanted onto the surfaces of rabbit Achilles, peroneus brevis, flexor profundus, and extensor longus tendons. The tendons were assessed by X-gal staining after 9 days, and by GFP fluorescence at 7, 14, and 21 days. Twenty percent to 50% of the treated cells stained for β-galactosidase at an MOI of 500. The GFP-labeled cells showed nearly 100% fluorescence at an MOI of 50. No positive cells were visible in the control group. The β-galactosidase and GFP-expressing cells remained viable for as long as 3 weeks. It is possible to introduce foreign genes into rabbit tendon cells, transplant the cells onto tendon surfaces, and maintain viability of the cell/tendon construct for several weeks.

We have developed HVJ (hemagglutinating virus of Japan; Sendai virus)-liposomes that are efficient in vitro and in vivo gene delivery vehicles using the fusion-mediated gene delivery. The HVJ-liposome was highly efficient for the introduction of oligonucleotides into cells in vivo as well as the transfer of genes less than 100 kbp without damaging cells. By coupling the Epstein-Barr (EB) virus replicon apparatus with HJV-liposomes, transgene expression was sustained in vitro and in vivo. Most animal organs were found to be suitable targets for the fusigenic-viral liposomes, and numerous gene therapy strategies using this system were successful in animals. Here we demonstrate cancer gene therapy using HVJ-liposomes.