We examined the efficiency and intracellular fate of oligodeoxy-nucleotides (ODN) in the central nervous system (CNS) after delivery with a hemagglutinating virus of Japan (HVJ)-liposome vector in vivo and in vitro. In primary cultured granular cells of the rat cerebellum, application of fluorescein isothiocyanate (FITC)-labeled ODN complexed with HVJ-liposomes in vitro resulted in strong fluorescence localized in nuclei that persisted for > or = 2 wk, in contrast to 3 days with ODN alone. In vivo ODN transfer was attempted by different approaches: infusions into the paraventricular nuclei of the hypothalamus and the lateral cerebroventricle. Injection of FITC-labeled ODN into the hypothalamus by the HVJ-liposome method produced a higher concentration and more persistent fluorescence than did injection of ODN alone. Administration of ODN into the lateral cerebroventricle with HVJ-liposomes yielded more conspicuous and prolonged fluorescence in the periventricular layer, predominantly in cell nuclei. Furthermore, the distribution of fluorescent cells was broader with the HVJ-liposome method. These results indicate that the HVJ-liposome method prolongs the half-life of ODN and concentrates them in cell nuclei. Thus it is an efficient method for ODN transfer and holds promise as a gene delivery method in the CNS.

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The effects of a demagnetizing field and an external static magnetic field on the effective Snoek’s product of textured Z-type hexagonal ferrite, which is the product of effective susceptibility and resonance frequency, were examined in order to apply the Z-type hexagonal ferrite to high-frequency devices. As a result, the demagnetizing field due to the thin plate geometry increased the resonance frequency and the effective Snoek’s product when a high-frequency magnetic field was applied parallel to the c-plane of the Z-type hexagonal ferrite. Moreover, the resonance frequency, effective susceptibility, and effective Snoek’s product of 7.7 GHz, 10.7, and 82.2 GHz, respectively, were obtained when an external magnetic field that was sufficient to saturate the Z-type hexagonal ferrite slab was applied parallel to the c-plane and perpendicular to the high-frequency magnetic field. Furthermore, the Landau–Lifshitz equation suggested that a large Snoek’s product of over 50 GHz could be obtained with an external static field as small as 31 kA/m, which is enough to saturate the Z-type hexagonal ferrite.

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The resonance frequency of a non-saturated Z-type hexagonal ferrite under a demagnetizing field effect was formulated. The permeabilities along the c-axis and the c-plane were measured by a specimen cut from the c-plane-textured Z-type ferrite, and the resonance frequency was measured as a μ″ peak. The resonance frequency measured from the permeability in the c-plane increases dramatically as the specimen’s thickness increases. On the other hand, the resonance frequency measured from the permeability along the c-axis remains fairly constant. We tried to analyze the reason for the large difference in the resonance frequency depending on the crystal orientation using multi-domain resonance theory. As a result, the resonance frequency of a textured Z-type ferrite has been expressed when the high frequency magnetic field is parallel and normal to the c-plane. Therefore, it is confirmed that a demagnetizing field increases the resonance frequency, especially when the high frequency magnetic field is parallel to the c-plane. This result would contribute to the development a high performance inductance element.