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Objective: To investigate the effects of angiotensin (Ang)-(1-7) on oxidative stress and functional changes in isolated rat hearts with myocardial ischemia-reperfusion (IR) injury., Methods: IR injury was induced in isolated rat hearts with the Langendorff' apparatus. The left ventricular systolic pressure (LVSP) of the rat heart was measured using a pressure transducer. Malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in the myocardium were detected using commercial kits., Results: Myocardial ischemia (15 min) and reperfusion (30 min) significantly increased myocardial levels of MDA, and reduced the SOD activity and LVSP (P<0.05). Pretreatment with Ang-(1-7) at 1.0 nmol/L 30 min before ischemia obviously inhibited IR-induced MDA increment and lowering of SOD activity and LVSP. Pretreatment of the rats with intraperitoneal injection of 5 mg/kg indomethacin 1 h before isolation of the heart markedly antagonized the effect of Ang-(1-7) on MDA production, SOD activity and LVSP., Conclusion: Angiotensin-(1-7) can inhibit IR injury-induced oxidative stress and decrease in cardiac contractile function in isolated rat hearts. The mechanism underlying the effect of Ang-(1-7) may be associated with increased secretion of prostaglandin.

Objective: To prepare resveratrol chitosan nanoparticles with free amine groups on the surface so as to conjugate ligands, which will actively target to special tissues or organs., Method: The chitosan nanoparticles with free amine on the surface was prepared by sodium chloride precipitation. Nanoparticles with different solidification degrees were studied on turbidity, in vitro release, encapsulation efficiency, drug loading and diameter., Result: The turbidity of nanoparticles with various solidification degrees decreased at different rates after ultrasonic or water bath heating treatment. All nanoparticles mentioned above obviously shew sustained release. The rate of release was slowed down with the increase of solidification agents. Solidification had no obvious effects on the encapsulation efficiency and drug loading. The diameter of chitosan nanoparticles with 200 microL solidification agents was 487 nm. The polydispersion was 0.144., Conclusion: The diameter of the prepared nanoparticles was relatively small. The amine on the surface was free, which offered the possibility of designing the acive target drug delivery system.

The two disease-resistance genes chitinase and glucanase, which were respectively directed by commelina yellow mottle virus promoter (CoYMV, vascular specific) and CaMV35S promoter, were introduced into cotton genome via Agrobacterium tumefaciens. Transgenic plants were obtained from two popularly cultivated varieties Jihe321 and CRIC35. After screening by spraying kanamycin over unfolding leaves, the kanamycin resistance (KmR) plants were tested by PCR and Southern blot. The results showed that there were one or two inserts of transgenes in cotton genome. Performance test of resistance of T3 families in field and greenhouse showed that seven lines were resistant or tolerant to Verticillium dahliea. Meanwhile, the resistance at seedling stage in greenhouse was in accordance with that at the boll-setting stage in field. Among the seven lines, D9910, D9915 and D9919 had a disease resistance index of 6.5, 9.4 and 9.5, respectively in field, which showed a high resistance level. Genetics analysis of the three lines showed a classical Mendelian pattern of one pair of genes, which meant that each of the three lines contains one copy of transgene. Southern blotting also confirmed the copy number of inserts.

Plasmid pBLGC containing chitinase gene from Phaseolus limensis and beta-1,3-glucanase gene from Nicotiana tabacum was bombarded into the restorer line "Nan29" of Dian-type hybrid rice (Oryza sativa L. ssp. japonica) from Yunnan province of South-west China. 93 regenerants were obtained from the calli that were resistant to G418 (100 to 150 mg/L) on NB medium. Using beta-1,3 glucanase gene as the probe, 17 of the regenerants were identified to be transgenic lines by dot blotting and the foreign genes construction were integrated into the genomes of T1 lines by Southern blotting hybridization. Two foreign genes were inherited stably to T4 generation according to PCR results of the lines. The resistance to rice blast of six transgenic lines were evaluated by inoculating four violent biological races of Magnaporthe grisea from Yunnan province and inducing the disease in the field. The results indicated that the resistance to rice blast of transgenic lines were enhanced to varying degrees compared with the receptor line and the transgenic lines could be used in rice blast resistant breeding.

This review comments on recent advances in research of disease resistance genes(R Genes) in defence system of plants. The R genes cloned up to date are summarized and classified roughly into four classes listed in the Table 1. The location and the function of the R proteins, i.e., the expressed products of different R genes in the cells are reviewed. In addition, the polymorphism of coding region of R genes, the different fashions of R gene arrangement on the chromosomes, and the evolution and origin of R genes are discussed.