Inhibitory effects of sulfated lentinan with different degree of sulfation against tobacco mosaic virus (TMV) in tobacco seedlings.

The inhibitory effects of sulfated lentinan with different degrees of sulfation against tobacco mosaic virus (TMV) and the underlying mechanism were investigated. The results indicated that plants treated with increasing concentrations of sulfated lentinan, with increasing numbers of treatments and with increasing time after treatment had a decrease in the number of necrotic lesions, indicating a long-term protection against TMV that mimics vaccination. In addition, the levels of TMV-capsid protein (CP) transcripts decreased in distant leaves, indicating that sulfated lentinan induces systemic protection against TMV. The activities of the defense enzymes phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) and the amounts of several phenylpropanoid compounds (PPCs) were measured in control and treated plants without infection. A progressive increase in PAL activity was observed with increasing time after treatment, together with the accumulation of free and conjugated PPCs. In contrast, LOX activity remained unchanged. Interestingly, the increase in PAL activity showed a linear correlation with the decrease in necrotic lesions and the decrease in TMV-CP transcript level. Thus, sulfated lentinan induced systemic and long-term protection against TMV in tobacco plants that is determined, at least in part, by a sustained activation of PAL and the accumulation of PPCs with potential antiviral activity.

[Implementation and preliminary experience of high-field intraoperative magnetic resonance imaging in the endoscopic chordoma operation with transsphenoidal or transoral approach].

OBJECTIVE: To review the preliminary clinical experience with high-field-strength intra-operative magnetic resonance imaging (iMRI) in the endoscopic chordoma operation with transsphenoidal or transoral approach. METHODS: From January 2009 to December 2010, 23 patients [range, 29 - 64 years, mean age (42 ± 3) years] of chordoma were operated with endoscopic transsphenoidal or transoral approach and examined intraoperatively with a movable 1.5 T iMRI magnet. Tumor size range was 2.0 - 5.7 cm, mean (3.5 ± 0.8) cm. A navigation system based on iMRI was used in 20 cases. RESULTS: iMRI scan were performed in each operation from 1 time to 5 times. Neuronavigation system were used in 20 operations and the data renewed in 12 cases by the information from iMRI. In 15 of 23 patients, iMRI had revealed residual lesions and resulted in 12 cases further treatment, eventually, 9 tumors were totally removed and 3 tumors were further removed. The ratio of total removal tumor was enhanced to 73.9% (17/23) from 34.8% (8/23). Among 15 cases of partial chordoma removal detected by scanning in operation, 9 were huge chordoma. The residual of huge chordoma detected by scanning in operation was 9/11, and other chordoma contributed to 6/12. There were no iMRI related safety issue or accident recorded in this study. CONCLUSIONS: High-field-strength iMRI provide high-quality images of tumor resection that allows intraoperative modification of the surgical strategy. Combined with the navigation system, iMRI is helpful to maximize the resection of the chordoma and benefit for the safety of endoscopic operation.