Background. The animal model with humanized liver is useful for testing drug metabolism and toxicity in preclinical studies. A mouse model has been reported in which the liver was repopulated more than 90% with human hepatocytes; however, in the rat, the target is far from being reached. In this study, we attempt to develop a humanized liver model with an immunodeficient rat. Methods. Rag1 knockout rats were treated with neonatal thymectomy. At 3 and 4 weeks of age, they were injected with hepatotoxin retrorsine; 2 weeks after, the animals were subjected to 70% partial hepatectomy and transplanted with immature human hepatocytes via portal vein. The recipients were also treated with anti-asialo GM1 antibody weekly from the day before transplantation and were injected with FK506 every 3 days after transplantation. Results. In Rag1 knockout rats, B lymphocytes were deleted almost completely in peripheral blood. However, T and natural killer (NK) lymphocytes were kept present. When they were treated additionally with neonatal thymectomy for T-lymphocyte deletion and suppressed neutralized NK lymphocytes with anti-asialo GM1, B, T, and NK cells in lymphocytes were reduced to very low levels of 0.75%, 1.58%, and 0.26%, respectively. After transplanting human donor hepatocytes into retrorsine-treated recipient livers, at week 3 the human cell-derived hepatic colonies were expanded in the recipient liver and the liver repopulation rate with human hepatocytes reached approximately 17%. The human hepatocyte-specific genes, albumin, CYP3A4, CYP2C18, and CYP2C9, also could be detected in the recipient rat. Conclusion. It is possible to generate a chimera animal with humanized liver in a novel severely immunodeficient rat model.

Recently various endoscopic fluorescence detection systems for bronchial cancer have been created. Most of the systems use laser light for the excitation of cancer fluorescence or autofluorescence. We developed a simplified system with conventional Xenon lamp and an image intensifier which do not require any laser equipment or tumor preferential photosensitizer. The results of autofluorescence diagnosis of bronchial cancer and dysplasia compared with those of conventional bronchoscopy in 62 regions were as follows.

Recently various endoscopic fluorescence detection systems for bronchial cancer have been created. Most of the systems use laser light for the excitation of cancer fluorescence or autofluorescence. We developed a simplified system with conventional Xenon lamp and an image intensifier which do not require any laser equipment or tumor preferential photosensitizer. The results of autofluorescence diagnosis of bronchial cancer and dysplasia compared with those of conventional bronchoscopy in 62 regions were as follows.

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From the powder mixtures of aluminium metal and natural graphite ground in a planetary ball mill, aluminium nitride was formed in air as the consequence of self-ignition and following self-propagation reactions. The mechanism for AlN formation in air is discussed by taking into consideration the possible reactions.

From the powder mixtures of aluminium metal and natural graphite ground in a planetary ball mill, aluminium nitride was formed in air as the consequence of self-ignition and following self-propagation reactions. The mechanism for AlN formation in air is discussed by taking into consideration the possible reactions.