[Analysis of the short-term results of pre fenestration and external branched thoracic endovascular aortic repair for aortic lesions].

Objective: To evaluate the short-term effect of left subclavian artery (LSA) reconstruction with pre fenestration and external branch thoracic endovascular aortic repair (TEVAR) in the treatment of aortic arch descending lesions. Methods: The clinical data of 79 patients with aortic diseases who received LSA reconstruction in Tianjin Medical University General Hospital from November 2015 to October 2019 were analyzed retrospectively. According to different LSA reconstruction methods, they were divided into the fenestrated group (group f) 50 cases and the external branched group (group b) 29 cases. The surgical success rate, intraoperative and postoperative complication rate, re-intervention rate, mortality rate, and the change of the true and false lumen area of the dissection were compared and analyzed. Results: There were no significant differences in the perioperative and recent total complication rate, secondary intervention rate and mortality between the two groups (χ²=0, 1.246, 0.156, all P>0.05). The operation time of group f [(123.0±40.7 min)] was significantly longer than that of group b ((84.2±16.3) min, t=2.173, P=0.034). The degree of false lumen thrombosis of the stent segment was better than that of the non-stent segment (χ²=7.213, 14.359, both P<0.05) in the two groups after surgery, but no significant difference between the two groups (χ²=1.510, 0.886, both P>0.05). There was no significant difference in the change rate of the true and false lumen on each plane of the dissection between the two groups (all P>0.05). Conclusions: Both fenestrated and external branched TEVAR reconstruction LSA have good safety and effectiveness in treating aortic arch descending lesions. The external branched TEVAR takes less time, has higher effectiveness for lesions with shorter landing zone, and has better aortic remodeling effect in the stent segment soon; and the fenestrated TEVAR has better economy.

Hydrogen sulfide modulates gastric acid secretion in rats via involvement of substance P and nuclear factor-κB signaling.

Hydrogen sulfide (H2S) promotes gastric acid secretion in rats. The present study aimed to test the hypothesis that H2S regulates this response via activating TRPV1 channel and through activation of the nuclear factor-κB (NF-κB) pathway. Male Wistar rats were randomly divided into the sodium hydrosulfide (NaHS, 100 µmol/kg b.w.) group, pyrrolidine dithiocarbamate (PDTC, 100 µmol/kg b.w.) group, PDTC (100 µmol/kg b.w.) + NaHS (100 µmol /kg b.w.) group, capsazepine (0.1 mM) + NaHS (100 µmol /kg b.w.) group and L703606 (0.1 mM) + NaHS (100 µmol /kg b.w.) group. The acidity of gastric juice before injection and after injection were determined by a pH meter. The results showed that sodium hydrosulfide (NaHS), an exogenous H2S donor, significantly reduced the pH of gastric juice when injected into the enterocoelia. Further, the promotional effect of NaHS on gastric acid secretion could be attenuated by capsazepine, a transient receptor potential vanilloid 1 (TRPV1) antagonist; L703606, a neurokinin 1 (NK1) receptor antagonist; and PDTC, a NF-κB inhibitor. The data from these experiments suggest that NaHS exerts an excitatory effect on gastric acid secretion possibly mediated by TRPV1 channel activation in sensory nerve terminals with the consequent release of substance P and in a NF-κB -dependent manner.

Dynamic characterization of recombinant Chinese hamster ovary cells containing an inducible c-fos promoter GFP expression system as a biomarker.

An inducible reporter gene system for Chinese Hamster Ovary (CHO-DHFR(-)) cells has been developed and characterized with respect to its dynamic properties. The reporter gene system consists of the human c-fos promoter and variants of the green fluorescence protein (GFP), either EGFP with enhanced fluorescence or its destabilized form d2EGFP. The expression of wild-type EGFP or its destabilized form was studied in CHO-DHFR(-) cells in response to serum addition or deprivation. It was shown that serum-induced c-fos promoter mediated EGFP expression was considerably higher than expression from the human CMV promoter, a strong, constitutive promoter preferentially used for high-level expression in CHO cells. However, EGFP was less suitable for studying expression dynamics than d2EGFP due to the protein's long half-life in mammalian cells. The use of d2EGFP resulted in a significant improvement in the dynamic characteristics of the biomarker, particularly when the recombinant cells were selected for high-level GFP expression by subcloning or fluorescence activated cell/sorting (FACS). GFP expression in different subclones and cell populations sorted by FACS was characterized with respect to its dynamic responses in the presence or absence of serum in the culture medium. Significant differences in the GFP expression dynamics were observed for the isolated cell populations. The experimental results indicate that cells with high-level GFP expression also have a faster dynamic response and are thus, desirable for practical application of the reporter gene system e.g. in toxicity monitoring.

Microfluidic hydrodynamic focusing based synthesis of POPC liposomes for model biological systems.

Lipid vesicles have received significant attention in areas ranging from pharmaceutical and biomedical engineering to novel materials and nanotechnology. Microfluidic-based synthesis of liposomes offers a number of advantages over the more traditional synthesis methods such as extrusion and sonication. One such microfluidic approach is microfluidic hydrodynamic focusing (MHF), which has been used to synthesize nanoparticles and vesicles of various lipids. We show here that this method can be utilized in synthesis of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) vesicles with controllable size. Since POPC is among the primary constituents of cellular membranes, this work is of direct applicability to modelling of biological systems and development of nano-containers with higher biologic compatibility for pharmaceutical and medical applications.