0.05).The serum concentrations of CK-MB changed unsignificantly between reperfusion and perfusion period in either group.In both groups LDH_1 level was less than that of LDH_2 during reperfusion period. Conclusion:Continuous potassic warm blood perfusion is reliable for myocardial protection.

Biofilms are surface-associated communities of microorganisms embedded within self-secreted extracellular polymeric substances, and a major cause of chronic and persistent infections. Respiratory Pseudomona aeruginosa infection is the leading reason for morbidity and mortality in cystic fibrosis patients. The formation of biofilms by P. aeruginosa in the airway is thought to increase persistence and antibiotic resistance during infection. Biofilm formation of P. aeruginosa is regulated by complicated signaling systems including quorum sensing and two-component systems that control the synthesis of extracellular polymeric substances. Furthermore, iron is an essential and scarce nutrient for bacteria and an important signal factor. P. aeruginosa has developed multiple iron uptake systems to sequester enough iron for its survival, with important regulatory roles in both release of virulence factors and formation of biofilms. In this review, we summarize recent advances in biofilm formation and its regulation along with the iron-uptake strategies in P. aeruginosa, to provide new insights and understanding to fight bacterial biofilms.

Objective To study the plasma D-dimer (DD) level changes in the patients with rheumatoid arthritis (RA), and to analyze its correlation with various clinical indicators. Methods Selected a total of 138 cases of RA patients and 50 cases of normal person as matched group the plasma D-dimer level and the correlation analysis with age, rheuma-toid factor (RF), erythrocyte sedimentation rate (ESR), visual analogue scale (VAS score)and platelet were analyzed. Results The level of D-dimer level in RA patients was significantly higher than that of healthy controls, and the dif-ference was statistically significant (P<0.01);The D-dimer level of high disease activity group and low disease activity group with RA patients were significantly higher than the remission groups of RA patients (P all <0.01); The D-dimer level in high disease activity group of RA patients was significantly higher than the low disease activity group (P<0.01); There were positive correlations between the D-dimer level and the age, ESR, VAS score, RF, platelet in all RA patients (P all <0.01). Conclusion There is high coagulation state in RA patients, so the D-dimer can be used as a clinical nonspecific inflammatory reaction index in patients with RA, and can direct the clinical treatment.

Zn lactate and SnF₂ were used as active compounds in the dentifrice. Here, their anti-biofilm effects were evaluated on Pseudomonas aeruginosa, Acinetobacter baumannii and Streptococcus mutans. The biofilm prevention/dispersal assay of P. aeruginosa PAO1 demonstrated that Zn lactate and SnF₂ can inhibit biofilm formation independently or by combined treatment. Zn lactate disrupted extracellular polysaccharides matrix formation and SnF₂ reduced the biomass of biofilm. Most importantly, the combination of Zn lactate and SnF₂ thoroughly abolished the biofilm formation of all three strains.

Biofilm is prevalent in various ecological niches, in which microbial cells interconnect with each other through extracellular polymeric substances including polysaccharides, extracellular DNA, and proteins. When living in biofilms, the microbial cells employ small signalling chemicals as their "language" to communicate mutually, and exhibit remarkable differences in physiology compared to those living in planktonic state. It has been proven that the development of biofilm is subject to the regulation of c-di-GMP, an important second messenger found in prokaryotes. Given its important roles of biofilms in microbial infection, industry application, plant-microbe interactions and environmental pollustion, biofilm is one of frontier research areas in microbiology. This special issue of "Biofilm and c-di-GMP" systematically reviews the current progresses in the multiple research frontiers, including biotechnology, infectious diseases, environmental microbiology and plant pathology, with special focus on the methods and techniques in biofilm research. We hope that the issue will boost the interest of students and young scientists in this exciting area of microbiology.