[Current management of acute Stanford type A aortic dissection complicated with mesenteric malperfusion].

The management of acute type A aortic dissection (aTAAD) with mesenteric malperfusion (MMP) is quite challenging as it is often associated with high mortality and poor outcomes, and an optimal treatment strategy is lack of consensus for this critically ill condition. Emergent open surgical repair of the ascending aorta is a life-saving operation and remains the standard of care for aTAAD with MMP, but is associated with a high rate of mortality. In recent years, reperfusion of superior mesenteric artery (SMA) by endovascular repair as the first treatment strategy in the treatment of aTAAD with MMP has been concerned and reported. Only endovascular repair and conservative medical treatment are also introduced in few cases with poor outcomes. There are many urgent issues that need to be addressed in current strategies. The optimal management strategies remain controversial, and further investigation and research are needed. These issues were addressed in this article.

Prokaryotic expression of a novel mouse pro-apoptosis protein PNAS-4 and application of its polyclonal antibodies

Mouse PNAS-4 (mPNAS-4) has 96 percent identity with human PNAS-4 (hPNAS-4) in primary sequence and has been reported to be involved in the apoptotic response to DNA damage. However, there have been no studies reported of the biological functions of mPNAS-4. In studies conducted by our group (unpublished data), it was interesting to note that overexpression of mPNAS-4 promoted apoptotic death in Lewis lung carcinoma cells (LL2) and colon carcinoma cells (CT26) of mice both in vitro and in vivo. In our studies, mPNAS-4 was cloned into the pGEX-6P-1 vector with GST tag at N-terminal in Escherichia coli strain BL21(DE3). The soluble and insoluble expression of recombinant protein mPNAS-4 (rmPNAS-4) was temperature-dependent. The majority of rmPNAS-4 was insoluble at 37°C, while it was almost exclusively expressed in soluble form at 20°C. The soluble rmPNAS-4 was purified by one-step affinity purification, using a glutathione Sepharose 4B column. The rmPNAS-4 protein was further identified by electrospray ionization-mass spectrometry analysis. The search parameters of the parent and fragment mass error tolerance were set at 0.1 and 0.05 kDa, respectively, and the sequence coverage of search result was 28 percent. The purified rmPNAS-4 was further used as immunogen to raise polyclonal antibodies in New Zealand white rabbit, which were suitable to detect both the recombinant and the endogenous mPNAS-4 in mouse brain tissue and LL2 cells after immunoblotting and/or immunostaining. The purified rmPNAS-4 and our prepared anti-mPNAS-4 polyclonal antibodies may provide useful tools for future biological function studies for mPNAS.