[Experimental study of the effect of liposome-mediated vascular endothelial growth factor gene on the flap survival in rats].

OBJECTIVE: To investigate the effect of VEGF gene on the random flap survival after pedicle division at different time in rats. METHODS: The random-pattern flaps were formed on the back of the 120 SD rats. PcDNAVEGF165 (gene) wrapped with liposome was injected into the flaps in experimental group (n = 40). The flaps in the two control groups were injected with PcDNA (n = 40) or saline (n = 40). 1, 3, 5, 7 days after injection, 10 rats in each group were randomly selected to performed pedicle division. 7 days after pedicle division, the rats were killed to measure the flap survival rate. The microvessels was studied by histologic examination. The expression of VEGF was assessed by immunohistochemical staining. The flaps were also examined under the electron ultrastructure microscopy. RESULTS: 1) Flap survival rate after pedicle division in experimental group at 1 day, 3 days, 5 days, 7 days after injection, were (45.45 +/- 12.24)%, (82.95 +/- 3.81)%, (85.00 +/- 3.38)%, (85.96 +/- 3.25)%, respectively. The flap survival rates were significant different between experimental group and the control groups at 3, 5, 7 days after injection (P < 0.05), but not at 1 days after injection (P > 0.05). 2) The average microvascular diameter and number in experimental group were significantly higher than those in control groups (P < 0.05). 3) The expression of VEGF in experimental group was significantly higher than that in the two control groups (P < 0.05). 4) Ultrastructure study showed more angiogenesis in experimental group. CONCLUSIONS: Subcutaneous injection of liposome-mediated VEGF gene can increase the survival rate of flap with early pedicle division. It is a simple, efficient, economic, and the relatively safe gene therapy.

Characterization of candidate class A, B and E floral homeotic genes from the perianthless basal angiosperm Chloranthus spicatus (Chloranthaceae).

The classic ABC model explains the activities of each class of floral homeotic genes in specifying the identity of floral organs. Thus, changes in these genes may underlay the origin of floral diversity during evolution. In this study, three MADS-box genes were isolated from the perianthless basal angiosperm Chloranthus spicatus. Sequence and phylogenetic analyses revealed that they are AP1-like, AP3-like and SEP3-like genes, and hence these genes were termed CsAP1, CsAP3 and CsSEP3, respectively. Due to these assignments, they represent candidate class A, class B and class E genes, respectively. Expression patterns suggest that the CsAP1, CsAP3 and CsSEP3 genes function during flower development of C. spicatus. CsAP1 is expressed broadly in the flower, which may reflect the ancestral function of SQUA-like genes in the specification of inflorescence and floral meristems rather than in patterning of the flower. CsAP3 is exclusively expressed in male floral organs, providing the evidence that AP3-like genes have ancestral function in differentiation between male and female reproductive organs. CsSEP3 expression is not detectable in spike meristems, but its mRNA accumulates throughout the flower, supporting the view that SEP-like genes have conserved expression pattern and function throughout angiosperm. Studies of synonymous vs nonsynonymous nucleotide substitutions indicate that these genes have not evolved under changes in evolutionary forces. All the data above suggest that the genes may have maintained at least some ancestral functions despite the lack of perianth in the flowers of C. spicatus.