[Correlation between Mic60 haploid insufficiency and cardiac aging in mouse].

Objective: To investigate the role of Mic60 in cardiac aging. Methods: Wild-type and Mic60(+ /-) male mice at age of 4-6 months (young group, n=6) and 18-20 months (aged group, n=9) were used. H&E and Masson staining of frozen and paraffin sections were subjected to morphologic evaluation of the cardiac tissue samples. SA-ß-Gal staining was utilized to detect the activity of senescence-associated ß-galactosidase. Western blot was performed to detect the expression of Mic60 and p21 in cardiac tissues. Results: Expression of Mic60 in mouse cardiac tissue increased in an age-dependent manner. Haploid insufficiency of Mic60 resulted in an increased left ventricular wall thickness [(1.32±0.09) mm vs.(1.12±0.09) mm, P<0.05], cardiomyocyte hypertrophy[(474.9±27.6) µm(2) vs.(358.8±48.7) µm(2), P<0.05] and interstitial fibrosis [ (38.24±7.58) ×10(3)µm(2) vs.(25.81±4.12)×10(3)µm(2,) P<0.05], increased activity of SA-ß-Gal (2.26±0.24 vs.0.25±0.05, P<0.01) and higher expression of p21 (P<0.01) in aged mouse cardiac tissue, but not in young mice. Conclusion: Haploid insufficiency of Mic60 leads to cardiac hypertrophy, interstitial fibrosis, increased activity of SA-ß-Gal and higher expression of p21 in aged cardiac tissue in mice, suggesting that Mic60 may prevent cardiac aging.

First isolation of Xanthomonas campestris from the blood of a Chinese woman.

Xanthomonas campestris isolated from the blood of a patient with a fever was first reported. Xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. Chinese cabbage, etc. Human infection due to X. campestris has not been reported so far. The characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. We believe that X. campestris is also one of the opportunistic pathogens, which can infect compromised host.