[Expression of ZmPIP1 subgroup genes in maize roots under water shortage].

To investigate the role of ZmPIP1-1 and ZmPIP1-2 in water uptake of roots and drought resistance of crops, semi-quantitative PCR was used to examine the expression of ZmPIP1-1 and ZmPIP1-2 in root systems of different maize genotypes under water deficit. These genotypes showed different resistance to water shortage under field conditions. The reference gene to target genes was tubulin. Maize seedlings were grown by hydroponics in a growth chamber. Water deficit was imposed on the seedlings with PEG-6000. The result showed that ZmPIP1-1 was up-regulated under water deficit in root systems of plants of the filial generation 'Hudan 4' and the mother line 'Tiansi', which were resistant to water shortage, but there was no noticeable up-regulation of ZmPIP1-1 in the root systems of the father line '803', which was sensitive to water deprivation. The result also showed that the extent of up-regulation was positively correlated with drought resistance of maize (Fig.3). On the other hand, the expression of ZmPIP1-1 showed different degrees of tendency after different duration of water stress in the root systems of the maize seedlings of different genotypes. The result showed that ZmPIP1-2 was identically expressed in three different species of maize and under different water conditions. The results support the theory that the intercellular water transport contributes to increased water uptake in root systems under water deficit by up-regulating the number of some kinds of aquaporins. The increases amount of transcripts of aquaporins is positively correlated to drought resistance of plant varieties. But not all kinds of number of aquaporins is up-regulated during water shortage, some kinds of aquaporins are identically expressed under water deficit conditions and well watered conditions.

[Use of recombinant human beta-defensin-3 to evaluate the effect of adhesion of Candida albicans on the surface of soft lining material].

PURPOSE: To evaluate the effectiveness of recombinant human beta-defensin-3 (rHBD3) on reduction of Candida albicans from the surface of soft lining materials. METHODS: Specimens made of soft lining materials, which had been contaminated with C. albicans, were immersed in 25 µg/mL rHBD3 and 5.25% sodium hypochlorite (a positive control) for 5, 10, 30 and 60 min. The results were analyzed statistically with SPSS 10.0 software package. Confocal laser scanning microscopy(CLSM) of biofilm-associated C. albicans were treated with rHBD3 in different times. RESULTS: The results confirmed that an immersion time of 30 min or higher yielded a good disinfection effect, both for the experimental group and the positive control. A large number of pathogenic bacteria were killed and the cells were stained red by SYTO9/PI after 30 min. CONCLUSIONS: It is possible that soft lining materials immersed in rHBD3 solution that possesses antifungal activity may be clinically protective.

[Experimental study of periosteal osteoblasts adhesion to artificial bone scaffolds based on rapid prototype].

OBJECTIVE: To study the biocompatibility of bone engineering scaffolds designed and fabricated by CAD and Rapid Prototyping techniques. METHODS: Infant rat calvarias osteoblasts were isolated and expanded in vitro and the cells (2nd passage) were seeded onto scaffolds with porosity 80%, 90%, 95% at a density of 2.06 x 10(9)/L. Cell adhesion number and morphology were measured with SEM after 4 days, 10 days co-culture. RESULTS: (1) The osteoblasts' adhesion amounts increased with culture time in three porosity group (P < 0.05), but the increase were different among three groups, 80% group was 0.35 x 10(5), 90% group was 2.84 x 10(5); (2) Through SEM observations, it showed that osteoblasts adhered to all scaffolds well. CONCLUSION: The scaffolds designed and fabricated by CAD and rapid prototyping own a good cellular biocompatibility. The results suggest the feasibility of using such scaffold fabricating method for bone tissue engineering research and clinical therapy.