8-Hydroxyquinoline derivatives induce the proliferation of rat mesenchymal stem cells (rMSCs)

A series of 8-hydroxyquinoline derivatives with different substituted groups at 2- or 5-position have been synthesized and characterized. Their effects on the proliferation of the rat marrow-derived mesenchymal stem cells (rMSCs) have been evaluated by MTT assay and flow cytometry. We also analyzed the ability of these compounds to regulate the proliferation of rMSCs and the relationship with the structures of 8-hydroxyquinoline. Compounds 8-11, in which, the vinyl-substituents are on the 2-position of 8-hydroxyquinoline, appear to be able to induce the proliferation of rMSCs. These results show that compounds 8-11 provide a kind of new substances for regulating the proliferation of rMSCs.

[Study on expression of the glycoprotein in myocardial cell membrane of the rat's early myocardial ischemic]

OBJECTIVE

To explore expression of the glycoprotein in early myocardial ischemic.

METHODS

The glycoprotein changes occurred at the early acute cardiac ischemic area induced experimentally by ligation of left coronary artery of 32 SD rats. 6 lectins were measured by means of immunohistochemical methods.

RESULTS

Positive staining of PNA could be observed in ischemic area at 5 min after ischemia, and the positive area increased with the prolongation of ischemic period. It became the strongest for 2 h and then decreased.

CONCLUSION

This experiment proved that myocardial cell membrane in ischemia expressed D-galactose. This may be of some value in forensic medicine practice.

Sudden death caused by stricture of the sinus node artery

The sudden unexpected deaths of two young people and the findings in their hearts at autopsy are described. The striking feature was marked narrowing of the sinus node arteries by fibromuscular dysplasia. There were no other histological abnormalities present elsewhere. The observations suggest that pathological changes of the sinus node arteries might lead to a terminal cardiac arrhythmia acting as the mechanism of death.

[Cloning and expression of an antifreeze peptide gene of winter flounder in E. coli]

Antifreeze peptide (AFP) produced in some animals is able to lower freezing temperature to prevent serum from freezing. There is a great potential to apply AFP in various circumstances wherever tolerance to cold environment is required. cDNA copies of AFP and proAFP coding sequence were synthesized according to the published sequence from a winter flounder (Pseudopleuronectes americanus). Expression of AFP or proAFP cDNA was initially tested in E. coli using a procaryotic expression vector. Level of the expression was essentially low indicated by SDS-PAGE and protein staining procedures. In order to detect the low level expression, the AFP (or proAFP) cDNA was fused, in frame, to the 5'-end of the CAT reporter gene resulting in a chimeric AFP/CAT (or proAFP/CAT) cDNA. The product translated from such a chimeric mRNA must contain a N'-terminal AFP (or proAFP) portion and C'-terminal CAT portion. Thus, low level of expression of AFP (or proAFP) in the fused form may be detected indirectly by sensitive CAT assay as long as the chimeric CAT still remains the activity. As expected, CAT activity has been clearly detected in protein extract from induced E. coli indicating that AFP (or proAFP) cDNA clones be expressed in E. coli.