[Effect of fertilization depth on 15N-urea absorption, utilization and loss in dwarf apple trees].

Five-year-old 'Fuji'3/M26/M. hupehensis Rehd. seedlings were treated by 15N tracer to study the effects of fertilization depth (0, 20 and 40 cm) on 15N-urea absorption, distribution, utilization and loss in soil. The results showed that the plant leaf area, chlorophyll content and total N of apple leaves in 20 cm treatment were obviously higher than 0 cm and 40 cm treatments. The 15N derived from fertilizer (Ndff) in different organs of apple plant under different depths were significantly different, and the Ndff was the highest in roots at the full-bloom stage, and then in perennial branches. During the shoot rapid-growing and flower bud differentiation stage, the Ndff of new organs higher than that of the storage organs, and the Ndff of different organs were high level at fruit rapid-expanding stage, and the Ndff of fruit was the highest. The distribution ratio of 15N at fruit maturity stage was significantly different under fertilization depths, and that of the vegetative and repro- ductive organs of 20 cm treatment were obviously higher than 0 cm and 40 cm treatments, but that of the storage organs of 20 cm treatment was lower than 0 cm and 40 cm treatments. At fruit maturity stage, 15N utilization rate of apple plant of 20 cm treatment was 24.0%, which was obviously higher than 0 cm (14.1%) and 40 cm (7.6%) treatments, and 15N loss rate was 54.0%, which was obviously lower than 0 cm (67.8%) and 40 cm (63.5%) treatments. With the increase of fertilization depths, the N residue in soil increased sharply.

Expression of CD44v6 and Livin in gastric cancer tissue.

BACKGROUND: CD44v6 plays an important role in invasion and metastasis of tumor, Livin has anti-apoptotic effects. The present study aimed to explore the expression and clinical significance of CD44v6 and Livin in gastric cancer tissue. METHODS: Streptavidin-peroxidase linked immunohistochemical method was used to determine the expression of CD44v6 and Livin in gastric cancer tissue and adjacent normal gastric tissues from 59 patients with histopathologically confirmed gastric cancer, and in gastric tissue specimens of 15 patients with gastric polyps, and 15 patients with chronic non-atrophic gastritis. The chi-square test was used for comparison of the relevant factors, Spearman's rank correlation test was applied for relationship among positive expression of the proteins. RESULTS: The expresion of CD44v6 was positive in 64.4% of the gastric cancer patients; 5.1%, 0 and 13.3% in specimens of normal tissues adjacent to the cancer tissues, in gastric tissue specimens of patients with gastric polyps, and patients with chronic non-atrophic gastritis, respectively. The expression of Livin was positive in 52.5% of the gastric cancer tissues, 6.8%, 0 and 6.7% in the adjacent normal gastric tissue, specimens of patients with gastric polyps and chronic non-atrophic gastritis, respectively. The expression of CD44v6 was significantly correlated with the depth of invasion, the degree of differentiation, and lymphnode metastasis of gastric cancer (P < 0.05). The positive expression rate of Livin protein was also significantly correlated with degree of differentiation of gastric cancer cells and metastasis to lymphnodes (P < 0.05), but not correlated with the depth of invasion and pathological types (P > 0.05). The expression of CD44v6 and Livin in the gastric cancer tissue was positively correlated (r(s) = 0.286, P = 0.028). CONCLUSIONS: The increased expression of CD44v6 and Livin in gastric cancer tissue may be closely related with development and progression of gastric cancer. CD44v6 and Livin may be new biological markers of gastric cancer.