[COX-2 and HO-1 are involved in the delayed preconditioning elicited by bradykinin in rat hearts].

Objective: To investigate whether cyclooxygenase-2 (COX-2) and heme oxygenase-1 (HO-1) are involved in the bradykinin-induced delayed protection.

Methods: Cardiac contractility, lactate dehydrogenase (LDH) and infarct area were analyzed in isolated rat hearts undergoing ischemia-reperfusion injury induced by Langendorff method.

Result: Conscious rats received bradykinin (40 microg/kg), and the isolated hearts were subjected to 30 min of regional ischemia and 120 min of reperfusion 24 h later.

Analysis of nucleotide sequences and multimeric forms of a novel satellite RNA associated with beet black scorch virus.

The full-length sequence of a satellite RNA (sat-RNA) of Beet black scorch virus isolate X (BBSV-X) was determined. This agent is 615 nucleotides long and lacks extensive sequence homology with its helper virus or with other reported viruses. Purified virus particles contained abundant single-stranded plus-sense monomers and smaller amounts of dimers.

N-methyl-N'-nitro-N-nitrosoguanidine sensitivity, mutator phenotype and sequence specificity of spontaneous mutagenesis in FEN-1-deficient cells.

Intact pZ189 DNA was allowed to replicate in FL-FEN-1(-) cell line that was established in this laboratory in which the expression of FEN-1 gene was blocked by dexamethasone-inducible expression of antisense RNA to FEN-1. E. coli MBM7070 was transfected with the replicated plasmid, and those with mutations in the supF gene were identified.

Establishment of Cell Line with the FEN-1 Gene Blocked by Its Antisense.

FEN-1 is a structure-specific endo/exonuclease, which is involved in the process of both DNA duplication and DNA repair. In this work a mammalian expression vector expressing antisense FEN-1 gene fragment pMAMneoAmp(-)FNB(-) was constructed, after cloning the NcoI-BamHI fragment of FEN-1 gene into the mammalian expression vector pMAMneoAmp(-) in antisense orientation. After FL cell was transfected with pMAMneoAmp(-)FNB(-) and selected by G418, the FL-FEN-1(-) cell line, in which the FEN-1 gene expression was blocked, was established.

The Influence of FEN-1 Gene on Cell Cycle and Genetic Stability.

FEN-1 is essential in the cell replication, repair and in the maintenance of cellular genetic stability. In this report, it was verfied that FEN-1 antisense mRNA fragment was expressed in the cell line FL-FEN-1(-),constructed in our lab, blocking FEN-1 gene expression. It was found by the flow cytometer analysis that the cell cycle of FL-FEN-1(-) cells was delayed in the S-phase DNA synthesis process and arrested in G(1) phase.

Wheat yellow mosaic virus Widely Occurring in Wheat (Triticum aestivum) in China.

Wheat yellow mosaic virus (WYMV) was identified in 25 of 27 wheat (Triticum aestivum) samples from six provinces in China using reverse-transcription polymerase chain reaction. Wheat spindle streak mosaic virus was not detected. Thus, contrary to previous reports, WYMV was the only bymovirus detected in wheat in China.