Effects of tumor necrosis factor and E-selectin on coronary artery flow.

OBJECTIVE: The aim of the study is to investigate the correlation between tumor necrosis factor (TNF-α), E-selectin and coronary artery flow following myocardial ischemia-reperfusion model (IR) in Yorkshire pigs. MATERIALS AND METHODS: Establishment of IR model in pigs. Following the injury model, Experiment group was administrated intravenously Shenfu injection solution (SFI, 1 mL/kg). The control group received the same amount of saline. After 30 min of blood reflux, thrombolysis in myocardial infarction frame count (TFC) was recorded following surgery. TNF-α, E-selectin expression was determined by ELISA in the venous sheath, coronary sinus, artery sinus, and proximal segment of the coronary artery. RESULTS: After the blood reflowing, TFC in both groups were upregulated, and TFC increased more than the control group. The difference is statistically significant (p<0.05) at the time of 30 min. TNF-α, E-selectin expression increased after IR. After reperfusion, TNF-α, E-selectin levels further increased and the myocardial injury was aggravated. SFI inhibited inflammation in the experimental group. TNF-α, E-selectin levels at coronary sinus, artery sinus, and distal segment of coronary artery after surgery was positively correlated with TIMI in the experimental group (p<0.05). TNF-α, E-selectin levels significantly increased after reperfusion (p<0.05). CONCLUSIONS: The result demonstrated that TNF-α, E-selectin levels were positively correlated with coronary artery reflow only in the experimental group but not in the control group.

Correlation study between interleukin-6 levels and coronary reflow.

OBJECTIVE: To analyze the correlation between local interleukin-6 (IL-6) levels in different parts of blood vessel and the record of Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) after myocardial ischemia-reperfusion (IR) model. MATERIALS AND METHODS: Establishment of IR model in Yorkshire pigs, the pigs were divided into two groups (n=6). Experiment group pigs were administrated with Shenfu injection (SF) intravenously (1 mL/kg), control group was given saline injection. The blood reflowed after 30 min. TIMI was recorded to evaluate the coronary blood flow and myocardial perfusion. IL-6 levels in venous sheath, coronary sinus, artery sinus, and proximal coronary artery were determined by ELISA. RESULTS: The records of TIMI in experimental group were higher than that in control group. The difference was statistically significant (p < 0.05). The level of IL-6 increased obviously compared with control group after reperfusion (p < 0.05). Shenfu injection reduced the level of IL-6. IL-6 level at the coronary sinus was positively correlated with TIMI in experimental group (p = 0.03, R2 = 0.97) but not in control group. CONCLUSIONS: IL-6 levels were significantly increased after reperfusion, which aggravated myocardial injury. IL-6 may be associated with coronary reflow, but further study is needed.

Simultaneous in situ detection of beta-interferon mRNA and DNA in the same cell.

We report a quantitative method that combines in situ mRNA hybridization with microfluorometric analysis of DNA content to detect gene expression in single cells of a heteroploid cell population. The model was a human fibrosarcoma HT1080 cell line which consisted of diploid and tetraploid cells that were induced with polyI:polyC for production of beta-interferon. The level of beta-interferon mRNA detected by in situ hybridization was found to be two to three times higher in tetraploid compared to diploid HT1080 cells, and correlated with beta-interferon activity in that a subclone of tetraploid HT1080 cells secreted two- to fivefold more beta-interferon than a subclone of diploid HT1080 cells. Interestingly, beta-interferon-related transcripts were detected during S-phase in uninduced tetraploid HT1080 cells. In addition, beta-interferon induced by polyI:polyC was expressed in all phases of the cell cycle as demonstrated with a human diploid fibroblast, HF926. The unique features offered by the combination of microfluorometry and in situ hybridization provide a valuable tool to investigate specific gene expression related to ploidy or cell-cycle stage in the same individual cell of an unsynchronized population. Since the method allows direct observation of morphology, one can be assured that all quantitative measurements were made on whole cells with intact nuclei.

Macromolecule synthesis in temperature-sensitive mutants of methanol-utilizing Hansenula polymorpha.

Temperature sensitive (ts) mutants of methanol-utilizing Hansenula polymorpha NTU-AM-P5 were isolated by UV irradiation, EMS and/or NTG treatment. They grow normally at permissive temperature (PT) 38 degrees C, but can not grow at restrictive temperature (RT) 46 degrees C. From chemical composition analysis, it was found that ts mutants NTU-AM-L2 and NTU-AM-L3 had higher RNA content than the others; while ts mutant NTU-AM-E19 had the highest protein content among the isolated strains. Leucinyl-tRNA synthetases activity was the highest among the twenty aminoacyl-tRNA synthetases in both wild type and their ts mutants. When the cells were shifted from PT to RT for 12 h, total aminoacyl-tRNA synthetase activity decreased in all tested strains. Leucinyl-tRNA synthetase of ts mutant NTU-AM-E10 decreased 91.23%. At RT, it was found that ts mutants NTU-AM-E10 and NTU-AM-E20 were defective in DNA synthesis; ts mutants NTU-AM-E15, NTU-AM-E20, NTU-AM-N37 and NTU-AM-m5 were defective in RNA synthesis; ts mutants NTU-AM-E10, NTU-AM-E20 and NTU-AM-m5 were somewhat defective in protein synthesis; while ts mutants NTU-AM-L2 and NTU-AM-L3 did not belong to any one of the above classifications.

Isolation and characterization of temperature-sensitive mutants of Hansenula.

For investigation of the feasibility of obtaining yeast strains with high protein and low nucleic acid content or high nucleic acid and low protein content for industrial production of single cell protein or nucleotide, the methanol-utilizing Hansenula polymorpha NTU-AM-P5 was chosen for isolation of temperature-sensitive mutants. Approximately 70 temperature-sensitive (ts) mutants were obtained. All of the ts mutants increased in cell size and aggregated when they were cultivated at permissive temperature and shifted to restrictive temperature in the late log phase or in the stationary phase. 86.1% of ts mutants had a lower growth rate than that of their wild-type. Only ts mutants, NTU-AM-L2, NTU-AM-E10, NTU-AM-E19, NTU-AM-E25 and NTU-AM-E30 had same or slightly higher than that of their wild-type strain. Cycloheximide at 1 mg/ml inhibited the growth of ts mutant NTU-AM-E19, but inhibited one-third of the other ts mutants, and their wild-type strain. Rifampicin at 0.1 mg/ml had an inhibitory activity on wild-type strain but not on ts mutant NTU-AM-E1. ts mutants NTU-AM-L2 and NTU-AM-E19 converted methanol to cell mass more efficiently than others. The ts mutants divided into two groups. One included absolute ts mutants, such as NTU-AM-E15 and NTU-AM-E20, which did not grow even in enriched media at restrictive temperature; the other group, such as NTU-AM-L2, NTU-AM-L3, NTU-AM-E10, NTU-AM-E19, NTU-AM-N37 and NTU-AM-m5, was auxotrophic ts mutants, which grew slightly in enriched media at restrictive temperature.