Because DNA degradation is mediated by secondary plant products such as phenolic terpenoids, the isolation of high quality DNA from plants containing a high content of polyphenolics has been a difficult problem. We demonstrate an easy extraction process by modifying several existing ones. Using this process we have found it possible to isolate DNAs from four fruit trees, grape (Vitis spp.), apple (Malus spp.), pear (Pyrus spp.) and persimmon (Diospyros spp.) and four species of conifer, Pinus densiflora, Pinus koraiensis,Taxus cuspidata and Juniperus chinensis within a few hours. Compared with the existing method, we have isolated high quality intact DNAs (260/280 = 1.8-2.0) routinely yielding 250-500 ng/microl (total 7.5-15 microg DNA from four to five tissue discs).

Gamma irradiation was used to reduce the N-nitrosamines and residual nitrite in model system sausage during storage. Aerobic or vacuum packaged sausage was irradiated at 0, 5, 10, 20, and 30 kGy. The residual nitrite levels were significantly reduced by gamma irradiation, and, in vacuum packaging, the reduction was dose dependent. The N-nitrosodimethylamine of the sausage irradiated at 10 kGy or above reduced in aerobic packaging, while a dose of 20 kGy was needed in vacuum packaging. The N-nitrosopyrrolidine reduction was found at 20 and 30 kGyirradiation. Results indicated that high dose irradiation ( > 10 kGy) was needed to reduce the carcinogenic Nnitrosamine and nitrite levels in pork sausage during storage.

An efficient and simple plant regeneration system via organogenesis from leaf segments of persimmon (Diospyros kaki Thunb.) cultivars`Fuyu' and`Nishimurawase' has been developed. The regeneration capacity was influenced by the culture vessels, gelling agents, plant growth regulators, and light conditions. Leaf explants taken from in vitro shoots were cultured on a modified Murashige and Skoog medium (MS 1 2 N) for 16 wk without transfer to fresh medium. Adventitious shoots appeared after 4 and 8 wk in culture of`Nishimurawase' and`Fuyu' tissues, respectively. The culture of leaf explants in Erlenmeyer flasks with medium containing 4 g l 21 agar enhanced shoot formation in comparison to media with increased agar concentrations. Optimal shoot regeneration was obtained with 5 mg l 21 (22.8 mM) zeatin and 0.1 mg l 21 (0.05 mM) indole-3-butyric acid (IBA) for`Nishimurawase', and 10 mg l 21 (45.6 mM) zeatin and 0.1 mg l 21 (0.05 mM) IBA for`Fuyu'. Shoot regeneration frequencies in both cultivars were 100%, and shoot numbers per explant reached up to 9.2 for`Nishimurawase' and 2.2 for`Fuyu'. Dark incubation during the first 4±5 wk was the most effective condition to successfully influence shoot regeneration in both cultivars. While dark incubation was essential for adventitious shoot formation by`Fuyu', it was only slightly beneficial to`Nishimurawase'. More than 80% of the regenerated shoots rooted within 4 wk on hormone-free MS 1 2 N medium after having been dipped for 30 s in 250 mg l 21 (1.1 mM) IBA solution.

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We investigated the frequency of gut inflammation and the role of gut lesion in the pathogenesis of the ankylosing spondylitis (AS) in Korean patients. Ileocolonoscopy and biopsy of the colon and terminal ileum were performed on 24 Korean patients with AS. Endoscopic lesions were observed in 7 patients (29.2%). The lesions were found more often in the terminal ileum (6/7) than in the colon (1/7). Histologic signs of gut inflammation were detected in 14 patients (58.3%), acute lesions in 2 patients (8.3%) and chronic lesions in 12 patients (50%). Gut inflammation were as frequently found in Korean patients with AS as in Western patients. These findings suggest that gut inflammation may play a role in the pathogenesis of AS in Korean patients as it does in Western patients.